Balance Mapping for the Extensible Provisioning Protocol (EPP)
draft-ietf-regext-balance-03
| Document | Type | Active Internet-Draft (regext WG) | |
|---|---|---|---|
| Authors | James Gould , Werner Staub , Dimitrios Melissovas | ||
| Last updated | 2026-09-24 | ||
| Replaces | draft-gould-regext-balance | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | Proposed Standard | ||
| Formats | |||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | Eric Skoglund | ||
| IESG | IESG state | I-D Exists | |
| Consensus boilerplate | Yes | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | eric.skoglund@internetstiftelsen.se |
draft-ietf-regext-balance-03
Network Working Group J. Gould
Internet-Draft VeriSign, Inc.
Intended status: Standards Track W. Staub
Expires: 28 March 2027 CORE
D. Melissovas
VeriSign, Inc.
24 September 2026
Balance Mapping for the Extensible Provisioning Protocol (EPP)
draft-ietf-regext-balance-03
Abstract
This document describes an Extensible Provisioning Protocol (EPP)
mapping for retrieving the client balance and other financial
information.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 28 March 2027.
Copyright Notice
Copyright (c) 2026 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Conventions Used in This Document . . . . . . . . . . . . 3
2. Object Attributes . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Currency . . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Decimal Attribute Values . . . . . . . . . . . . . . . . 3
2.3. Balance . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.4. Balance Available . . . . . . . . . . . . . . . . . . . . 5
2.5. Credit Line . . . . . . . . . . . . . . . . . . . . . . . 5
2.6. Cash Balance . . . . . . . . . . . . . . . . . . . . . . 6
2.7. Execution Limit . . . . . . . . . . . . . . . . . . . . . 6
2.8. Notification Threshold . . . . . . . . . . . . . . . . . 7
2.9. Dates and Times . . . . . . . . . . . . . . . . . . . . . 7
2.10. Cash Balance by Currency . . . . . . . . . . . . . . . . 7
2.11. Financial Examples . . . . . . . . . . . . . . . . . . . 11
3. Low Balance Poll Message . . . . . . . . . . . . . . . . . . 13
4. EPP Command Mapping . . . . . . . . . . . . . . . . . . . . . 17
4.1. EPP Query Commands . . . . . . . . . . . . . . . . . . . 17
4.1.1. EPP <check> Command . . . . . . . . . . . . . . . . . 17
4.1.2. EPP <info> Command . . . . . . . . . . . . . . . . . 17
4.1.3. EPP <transfer> Command . . . . . . . . . . . . . . . 21
4.2. EPP Transform Commands . . . . . . . . . . . . . . . . . 22
4.2.1. EPP <create> Command . . . . . . . . . . . . . . . . 22
4.2.2. EPP <delete> Command . . . . . . . . . . . . . . . . 22
4.2.3. EPP <renew> Command . . . . . . . . . . . . . . . . . 22
4.2.4. EPP <transfer> Command . . . . . . . . . . . . . . . 22
4.2.5. EPP <update> Command . . . . . . . . . . . . . . . . 22
5. Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . . 22
5.1. Balance Mapping Schema . . . . . . . . . . . . . . . . . 22
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25
6.1. XML Namespace . . . . . . . . . . . . . . . . . . . . . . 25
6.2. EPP Extension Registry . . . . . . . . . . . . . . . . . 25
7. Security Considerations . . . . . . . . . . . . . . . . . . . 26
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 26
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 26
9.1. Normative References . . . . . . . . . . . . . . . . . . 26
9.2. Informative References . . . . . . . . . . . . . . . . . 27
Appendix A. Change History . . . . . . . . . . . . . . . . . . . 27
A.1. Change from 00 to REGEXT 00 . . . . . . . . . . . . . . . 27
A.2. Change from REGEXT 00 to REGEXT 01 . . . . . . . . . . . 27
A.3. Change from REGEXT 01 to REGEXT 02 . . . . . . . . . . . 27
A.4. Change from REGEXT 02 to REGEXT 03 . . . . . . . . . . . 28
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 28
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1. Introduction
This document describes an extension mapping for version 1.0 of the
Extensible Provisioning Protocol (EPP) [RFC5730]. This EPP mapping
enables a client to get their financial information including the
balance available, credit line, cash balance, execution limit, and
notification threshold.
1.1. Conventions Used in This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
XML is case sensitive. Unless stated otherwise, XML specifications
and examples provided in this document MUST be interpreted in the
character case presented in order to develop a conforming
implementation.
In examples, "C:" represents lines sent by a protocol client and "S:"
represents lines returned by a protocol server. In examples,
indentation and whitespace are provided only to illustrate element
relationships and are not a required feature of this protocol.
"balance-0.4" is used as an abbreviation for
"urn:ietf:params:xml:ns:epp:balance-0.4". The XML namespace prefix
"balance" is used, but implementations MUST NOT depend on it.
Instead, they are to employ a proper namespace-aware XML parser and
serializer to interpret and output the XML documents.
2. Object Attributes
2.1. Currency
The <balance:currency> element is used to indicate the currency of
the balance elements that are determined by the server. The value of
this element MUST be a three-character currency code from
[ISO4217_2015].
2.2. Decimal Attribute Values
All the EPP Balance object attributes use the XML decimal
(http://www.w3.org/TR/2004/REC-xmlschema-2-20041028/#decimal) data
type to represent the currency value in the currency of the server.
The precision is restricted to 2 fractional digits.
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2.3. Balance
In the context of a commercial relationship, a client MAY have one or
more Balance accounts on the same server. Each Balance identifies
the amount in favor of the client, or in favor of the server and have
a "name" attribute that MUST be unique for the same client-server
relationship. The value of the "name" property is up to server
policy. When a server holds only one Balance account for a client,
then the "name" attribute of that Balance is OPTIONAL. In the
finance world, there are different ways to express current account
balance. The amount shown as "balance" and its mathematical sign
depend on whether it expresses:
* the amount available to the client at a Balance on the server for
billable transactions ("Balance Available", used in this
document).
* the balance in favor of the client in a Balance ("Cash Balance",
also used in this document);
* the balance in favor of the server in a Balance ("Balance
Outstanding", not used in this document, but may be used in
invoices).
A balance is the result of four types of transactions: charges,
refunds, deposits and withdrawals. When the balance is expressed in
terms of Balance Available or in terms or Cash Balance, as is the
case in this document, individual transactions are expressed with
positive or negative signs as follows:
* A charge to the client's Balance, a debit book entry, is expressed
as a negative number.
* A refund to the client's Balance, a credit book entry, is
expressed as a positive number.
* A deposit of funds to the Balance by the client is expressed as a
positive number.
* A withdrawal of funds from the Balance by the client is expressed
as a negative number.
In order to minimize the risk of misunderstandings, this document
calls for the balance to be expressed both in terms of Balance
Available(BA) and Cash Balance(CB) as defined below. The
relationship between them is shown by the following equation:
Balance Available(BA) = Credit Line(CL) + Cash Balance(CB)
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Figure 1: Balance Available Equation
Different Balances for the same client-server relationship MAY use
different main Currency Code (Section 2.1) or MAY use same Currency
Code (Section 2.1) E.g., a client is allowed to have the following 3
different Balances the same server:
* A Balance with name attribute "main", in USD currency.
* A Balance with name attribute "alt", also in USD currency.
* A with name attribute "euro", in EUR currency.
2.4. Balance Available
The <balance:balanceAvailable> element of a Balance represents the
calculated Balance Available value, using Balance Available Equation
(Figure 1) and the Currency Code (Section 2.1). The Balance
Available determines whether the Notification Threshold (Section 2.8)
or the Execution Limit (Section 2.7) are met when the "basedOn"
attribute is set to "balanceAvailable", which is the default value.
The Balance Available can be positive or negative. The Balance
Available increases when the Credit Line increases by adding more
credit instruments and increases when the Cash Balance increases with
client payments or applying billable credits to the client Balance.
The Balance Available decreases when the Credit Line decreases by
credit instruments being removed or expiring and decreases when the
Cash Balance decreases by applying billable debits. The Balance
Available value that disables the ability for the client to perform
future billable transactions on a Balance is defined by the Execution
Limit (Section 2.7), when the "basedOn" attribute is set to
"balanceAvailable".
2.5. Credit Line
The <balance:creditLine> element of a Balance represents the
calculated level of credit based on the set of active credit
instruments. The set of supported credit instruments is up to server
policy, with examples including a Line of Credit and an Emergency
Credit. Increasing the Credit Line(CL) results in increasing the
Balance Available(BA) in the Balance Available Equation (Figure 1),
and decreasing the Credit Line(CL) results in decreasing the Balance
Available(BA). A Credit Client is a client that works off of credit
represented by the Credit Line on a Balance. The Credit Line SHOULD
NOT be a negative value with the default value being "0.00".
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2.6. Cash Balance
The <balance:cashBalance> element of a Balance represents the cash on
hand that is impacted by client payments and billable transaction
debits and credits, inclusive of the fees and taxes. An example is a
Domain Create Command debiting (decreasing) the Cash Balance and a
grace period Domain Delete Command crediting (increasing) the Cash
Balance. Increasing the Cash Balance(CB) results in increasing the
Balance Available(BA) in the Balance Available Equation (Figure 1),
and decreasing the Cash Balance(CB) results in decreasing the Balance
Available(BA). A Cash Client is a client that works off of the Cash
Balance(CB) and not the Credit Line (Section 2.5) in a Balance.
The Cash Balance can be positive or negative, where the Execution
Limit (Section 2.7) determines if the client can perform future
billable transactions on their Balance.
* A positive cash balance is a balance in favor of the client, i.e.,
a credit balance and an asset for the client.
* A negative cash balance is a balance in favor of the server, i.e.,
a debit balance and a liability for the client.
2.7. Execution Limit
The <balance:executionLimit> element of a Balance is expressed in
terms of Balance Available (Section 2.4) when the "basedOn" attribute
is "balanceAvailable", or in terms of Cash Balance (Section 2.6) when
the "basedOn" attribute is "cashBalance". The "basedOn" attribute
MUST be set to the same value as the Notification Threshold
(Section 2.8) when the Notification Threshold (Section 2.8) is set.
It represents the limit that disables the ability for the client to
perform future billable transactions on a Balance. The default value
of the Execution Limit is zero ("0.00"), but a server MAY allow for a
positive or negative Execution Limit that is reflected by the
<balance:executionLimit> element.
* A positive Execution Limit requires a positive minimum Balance
Available (Section 2.4) or Cash Balance (Section 2.6); i.e.,
billable transactions initiated by the client are already blocked
before the full Balance Available (Section 2.4) or Cash Balance
(Section 2.6) is fully used. This may be done to keep a safety
margin for server-initiated billable transactions, such as auto-
renewals, or other costs.
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* A negative Execution Limit means that Balance Available
(Section 2.4) or Cash Balance (Section 2.6) is allowed to take a
negative value; i.e., it allows that amount of additional billable
transactions beyond the Balance Available (Section 2.4) or Cash
Balance (Section 2.6) to be initiated by the client.
2.8. Notification Threshold
The OPTIONAL <balance:notificationThreshold> element of a Balance is
expressed in terms of Balance Available (Section 2.4) when the
"basedOn" attribute is "balanceAvailable", or in terms of Cash
Balance (Section 2.6) when the "basedOn" attribute is "cashBalance".
The "basedOn" attribute MUST be set to the same value as the
Execution Limit (Section 2.7). It represents the threshold that
triggers the server to insert a Low Balance Poll Message (Section 3).
When the Available Balance of a Balance becomes reaches or goes below
the Notification Threshold, the server MUST insert a single Low
Balance Poll Message (Section 3) for that Balance.
2.9. Dates and Times
Date and time attribute values MUST be represented in Universal
Coordinated Time (UTC) using the Gregorian calendar. The extended
date-time form using upper case "T" and "Z" characters defined in XML
Schema Part 2 (http://www.w3.org/TR/2004/REC-xmlschema-2-20041028/)
MUST be used to represent date-time values, as XML Schema does not
support truncated date-time forms or lower case "T" and "Z"
characters.
2.10. Cash Balance by Currency
The Cash Balance by Currency of a Balance, represented by an OPTIONAL
list of <balance:cashBalanceByCurrency> elements, defines the
breakdown of the Cash Balance (Section 2.6) by currency for multi-
currency Balances. A Balance may hold a cash balance in many
currencies, which needs to be combined a converted to a single
currency in the Cash Balance (Section 2.6). The sum of all of the
<balance:cashBalanceByCurrency> elements MUST equal the
<balance:cashBalance> element in the currency in the
<balance:currency> element. The <balance:cashBalanceByCurrency>
element has the following attributes:
* "cashCurrency": the specific currency in which that component of
the balance is originally kept.
* "amount": the original value of the balance component prior to
translation.
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* "rate": the precise conversion factor applied to translate that
amount into the reference currency.
In financial applications, exchange rates can be represented via two
distinct conventions:
* Direct quotation: how much of the reference currency you get in
exchange for one unit of the original currency.
- Example: assuming the reference currency is the USD, if EUR
1.00 buys USD 1.1234 then the direct quotation is 1.1234.
* Indirect quotation: how much of the original currency you get in
exchange for one unit of the reference currency.
- Example: assuming the reference currency is the USD, if USD
1.00 buys EUR 0.8902 then the indirect quotation is 0.8902.
The direct quotation system is used in this document.
Example single currency balance info response. The account is
composed of a single balance in one currency: USD -200 (meaning that
the client owes the server USD 200). The overall cash balance
expressed in <balance:cashBalance> is equal to -200 USD.
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S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
S: <response>
S: <result code="1000">
S: <msg>Command completed successfully</msg>
S: </result>
S: <resData>
S: <balance:infData
S: xmlns:balance="urn:ietf:params:xml:ns:epp:balance-0.4">
S: <balance:balance>
S: <balance:currency>USD</balance:currency>
S: <balance:cashBalanceByCurrency
S: cashCurrency="USD"
S: amount="-200.00"
S: rate="1.0000">
S: -200.00
S: </balance:cashBalanceByCurrency>
S: <balance:balanceAvailable>
S: 800.00
S: </balance:balanceAvailable>
S: <balance:creditLine>1000.00</balance:creditLine>
S: <balance:cashBalance>-200.00</balance:cashBalance>
S: <balance:executionLimit>-500.00</balance:executionLimit>
S: <balance:notificationThreshold>
S: 500.00
S: </balance:notificationThreshold>
S: </balance:balance>
S: </balance:infData>
S: </resData>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
Example multi-currency translation balance info response. The
account is composed of two balances in two currencies: USD -200 and
EUR -100 (meaning that the client owes the server USD 200 and EUR
100). The overall cash balance expressed in <balance:cashBalance>
results from the aggregation of all cash balance items. After
translating the EUR into USD using a rate of 1.1234, the cash balance
is equal to -312.34 USD.
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S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
S: <response>
S: <result code="1000">
S: <msg>Command completed successfully</msg>
S: </result>
S: <resData>
S: <balance:infData
S: xmlns:balance="urn:ietf:params:xml:ns:epp:balance-0.4">
S: <balance:balance>
S: <balance:currency>USD</balance:currency>
S: <balance:cashBalanceByCurrency
S: cashCurrency="USD"
S: amount="-200.00"
S: rate="1.0000">
S: -200.00
S: </balance:cashBalanceByCurrency>
S: <balance:cashBalanceByCurrency
S: cashCurrency="EUR"
S: amount="-100.00"
S: rate="1.1234">
S: -112.34
S: </balance:cashBalanceByCurrency>
S: <balance:balanceAvailable>
S: 687.66
S: </balance:balanceAvailable>
S: <balance:creditLine>1000.00</balance:creditLine>
S: <balance:cashBalance>-312.34</balance:cashBalance>
S: <balance:executionLimit>-500.00</balance:executionLimit>
S: <balance:notificationThreshold>
S: 500.00
S: </balance:notificationThreshold>
S: </balance:balance>
S: </balance:infData>
S: </resData>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
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2.11. Financial Examples
The following examples provide a graphical representation of the
single-currency and multi-currency XML responses described in Cash
Balance by Currency (Section 2.10). They utilize the exact same
numeric values to visually map out the relationship between the
balance elements. The following abbreviations are used in the
diagrams:
* BA = Balance Available (<balance:balanceAvailable>)
* CL = Credit Line (<balance:creditLine>)
* CB = Cash Balance (<balance:cashBalance>)
* CBbC = Cash Balance by Currency (<balance:cashBalanceByCurrency>)
* NT = Notification Threshold (<balance:notificationThreshold>)
* EL = Execution Limit (<balance:executionLimit>)
Example single currency balance info response:
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^ Balance Available (USD)
|
|
1000 | +----------+ +----------+
| | CL | | CB |
| | =1000.00 | | =-200.00 |
800 .| |. . . . . |. +----------+
| | | ^
| | | |
| | | |
500 .|.|..........|.......|.............NT=500.00
| | | |
| | | | BA=800.00
| | | |
| | | |
| | | v
0 +-------------------------------------------->
|
|
|
|
|
-500 .|..................................EL=-500.00
|
|
v
Figure 2: Graphical representation of the single currency balance
response
Example multicurrency balance info response:
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^ Balance Available (USD)
|
|
1000 | +----------+ +----------+ ^
| | CL | | CBbC_USD | |
| | =1000.00 | | =-200.00 | (rate=1.1234) |
800 .| |. . . . . |. +----------+ +-----------------+ | CB=-312.34
| | | | CBbC_EUR=-100.00| |
687.66.| |. . . . . |. . . . . . . .+-----------------+ v
| | | ^
| | | |
| | | |
| | | |
| | | |
500 .|.|..........|.....................|................NT=500.00
| | | |
| | | | BA=687.66
| | | |
| | | |
| | | v
0 +------------------------------------------------------------>
|
|
|
|
|
-500 .|...................................................EL=-500.00
|
|
v
Figure 3: Graphical representation of the multi-currency balance
response
In the above example, the Cash Balance(CB) is calculated, as follows:
Cash Balance(CB) = SUM Cash Balance by Currency(CBbC)
Figure 4: Cash Balance Equation
3. Low Balance Poll Message
The EPP <poll> command and response is defined in section 2.9.2.3 of
[RFC5730]. For Balances that support a Notification Threshold
(Section 2.8), the Balance Info Response, as defined in
Section 4.1.2, the server inserts into the poll queue whenever the
Balance Available (Section 2.4) or Cash Balance (Section 2.6) for a
Balance reaches or goes below the Notification Threshold
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(Section 2.8). In the same message, the Low Balance Poll message MAY
identify one or more Balance accounts that are affected. The Low
Balance Poll message MUST include the "name" attribute for the
Balances it communicates, when the Balance accounts contain the
"name" attribute
Example <poll> command:
C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
C: <command>
C: <poll op="req"/>
C: <clTRID>ABC-12345</clTRID>
C: </command>
C:</epp>
Example low balance <poll> response when Balance contains no "name":
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S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
S: <response>
S: <result code="1301">
S: <msg>Command completed successfully; ack to dequeue</msg>
S: </result>
S: <msgQ count="1" id="12345">
S: <qDate>2026-03-18T15:25:01.0078Z</qDate>
S: <msg>Low Balance</msg>
S: </msgQ>
S: <resData>
S: <balance:infData
S: xmlns:balance="urn:ietf:params:xml:ns:epp:balance-0.4">
S: <balance:balance>
S: <balance:currency>USD</balance:currency>
S: <balance:balanceAvailable>
S: 200.00
S: </balance:balanceAvailable>
S: <balance:creditLine>1000.00</balance:creditLine>
S: <balance:cashBalance>-800.00</balance:cashBalance>
S: <balance:executionLimit>0.00</balance:executionLimit>
S: <balance:notificationThreshold>
S: 500.00
S: </balance:notificationThreshold>
S: </balance:balance>
S: </balance:infData>
S: </resData>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
Example low balance <poll> response for multiple Balances, when they
contain "name" attributes:
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S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
S: <response>
S: <result code="1301">
S: <msg>Command completed successfully; ack to dequeue</msg>
S: </result>
S: <msgQ count="1" id="12345">
S: <qDate>2026-03-18T15:25:01.0078Z</qDate>
S: <msg>Low Balance</msg>
S: </msgQ>
S: <resData>
S: <balance:infData
S: xmlns:balance="urn:ietf:params:xml:ns:epp:balance-0.4">
S: <balance:balance name="Acme Inc.">
S: <balance:currency>USD</balance:currency>
S: <balance:balanceAvailable>
S: 200.00
S: </balance:balanceAvailable>
S: <balance:creditLine>1000.00</balance:creditLine>
S: <balance:cashBalance>-800.00</balance:cashBalance>
S: <balance:executionLimit>0.00</balance:executionLimit>
S: <balance:notificationThreshold>
S: 500.00
S: </balance:notificationThreshold>
S: </balance:balance>
S: <balance:balance name="Example Inc.">
S: <balance:currency>USD</balance:currency>
S: <balance:balanceAvailable>
S: 400.00
S: </balance:balanceAvailable>
S: <balance:creditLine>500.00</balance:creditLine>
S: <balance:cashBalance>-100.00</balance:cashBalance>
S: <balance:executionLimit>-300.00</balance:executionLimit>
S: <balance:notificationThreshold>
S: 600.00
S: </balance:notificationThreshold>
S: </balance:balance>
S: </balance:infData>
S: </resData>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
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4. EPP Command Mapping
A detailed description of the EPP syntax and semantics can be found
in the EPP core protocol specification [RFC5730]. The command
mappings described here are specifically for use with the Balance
Object Mapping.
4.1. EPP Query Commands
EPP [RFC5730] provides three commands to retrieve object information:
<check> to determine if an object is known to the server, <info> to
retrieve detailed information associated with an object, and
<transfer> to retrieve object transfer status information.
4.1.1. EPP <check> Command
Available check semantics do not apply to balance objects, so there
is no mapping defined for the EPP <check> command.
4.1.2. EPP <info> Command
EPP provides the <info> command that is used to retrieve client
balance and other financial information for the currently logged-in
client. In addition to the standard EPP command elements, the <info>
command MUST contain a <balance:info> element that identifies the
balance namespace. The <balance:info> element does not contain any
child elements.
Example <info> command:
C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
C: <command>
C: <info>
C: <balance:info
C: xmlns:balance="urn:ietf:params:xml:ns:epp:balance-0.4"/>
C: </info>
C: <clTRID>ABC-12345</clTRID>
C: </command>
C:</epp>
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When an <info> command has been processed successfully, the EPP
<resData> element MUST contain a child <balance:infData> element that
identifies the balance namespace. The <balance:infData> element
contains one or more <balance:balance> child elements. Each
<balance:balance> element identifies a Balance (Section 2.3) object
of the client, with "name" attribute that is unique for the client-
server relationship. If there exists only one Balance account, the
"name" attribute is OPTIONAL. Each <balance:balance> contains the
following child elements:
<balance:currency>
The <balance:currency> element is used to indicate the Currency
(Section 2.1) used by the Balance account.
<balance:balanceAvailable>
The <balance:balanceAvailable> element contains the calculated
Balance Available (Section 2.4) of the Balance using the Currency
(Section 2.1) of the <balance:currency> element.
<balance:creditLine>
The <balance:creditLine> element contains the calculated Credit
Line (Section 2.5) of the Balance based on the set of active
credit instruments using the Currency (Section 2.1) of the
<balance:currency> element.
<balance:cashBalance>
The <balance:cashBalance> element that contains the Cash Balance
(Section 2.6) of the Balance representing the cash on hand that
is impacted by client payments and billable transaction debits
and credits using the Currency (Section 2.1) of the
<balance:currency> element.
<balance:executionLimit>
The OPTIONAL <balance:executionLimit> element, with a default
value of "0.00", that contains the Execution Limit (Section 2.7)
representing the value that disables the ability for the client
to perform future billable transactions on the Balance using the
Currency (Section 2.1) of the <balance:currency> element. The
OPTIONAL "basedOn" attribute determines whether the element value
is based on the <balance:balanceAvailable> element or the
<balance:cashBalance> element, with attribute values of
"balanceAvailable" and "cashBalance", respectively, and a default
of "balanceAvailable".
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<balance:notificationThreshold>
The OPTIONAL <balance:notificationThreshold> element that
contains the Notification Threshold (Section 2.8) representing
the value that triggers the server to insert a Low Balance Poll
Message (Section 3) using the Currency (Section 2.1) of the
<balance:currency> element. The OPTIONAL "basedOn" attribute
determines whether the element value is based on the
<balance:balanceAvailable> element or the <balance:cashBalance>
element, with attribute values of "balanceAvailable" and
"cashBalance", respectively, and a default of "balanceAvailable".
Example <info> response with the <balance:executionLimit> and
<balance:notificationThreshold> elements based on the default of
"balanceAvailable":
S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
S: <response>
S: <result code="1000">
S: <msg>Command completed successfully</msg>
S: </result>
S: <resData>
S: <balance:infData
S: xmlns:balance="urn:ietf:params:xml:ns:epp:balance-0.4">
S: <balance:balance>
S: <balance:currency>USD</balance:currency>
S: <balance:balanceAvailable>
S: 800.00
S: </balance:balanceAvailable>
S: <balance:creditLine>1000.00</balance:creditLine>
S: <balance:cashBalance>-200.00</balance:cashBalance>
S: <balance:executionLimit>-500.00</balance:executionLimit>
S: <balance:notificationThreshold>
S: 500.00
S: </balance:notificationThreshold>
S: </balance:balance>
S: </balance:infData>
S: </resData>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
Example <info> response with the <balance:executionLimit> and
<balance:notificationThreshold> elements based on the "cashBalance":
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S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
S: <response>
S: <result code="1000">
S: <msg>Command completed successfully</msg>
S: </result>
S: <resData>
S: <balance:infData
S: xmlns:balance="urn:ietf:params:xml:ns:epp:balance-0.4">
S: <balance:balance>
S: <balance:currency>USD</balance:currency>
S: <balance:balanceAvailable>
S: 800.00
S: </balance:balanceAvailable>
S: <balance:creditLine>1000.00</balance:creditLine>
S: <balance:cashBalance>-200.00</balance:cashBalance>
S: <balance:executionLimit basedOn="cashBalance">
S: -500.00
S: </balance:executionLimit>
S: <balance:notificationThreshold basedOn="cashBalance">
S: 500.00
S: </balance:notificationThreshold>
S: </balance:balance>
S: </balance:infData>
S: </resData>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
Example <info> response with a Balance account per Top Level Domain
(TLD) ("FOO", "BAR", and "BAZ"). "FOO" and "BAR" use USD as main
Currency, whereas "BAZ" uses EUR as main Currency:
S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
S: <response>
S: <result code="1000">
S: <msg>Command completed successfully</msg>
S: </result>
S: <resData>
S: <balance:infData
S: xmlns:balance="urn:ietf:params:xml:ns:epp:balance-0.4">
S: <balance:balance name="FOO">
S: <balance:currency>USD</balance:currency>
S: <balance:balanceAvailable>
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S: 800.00
S: </balance:balanceAvailable>
S: <balance:creditLine>1000.00</balance:creditLine>
S: <balance:cashBalance>-200.00</balance:cashBalance>
S: <balance:executionLimit>-500.00</balance:executionLimit>
S: <balance:notificationThreshold>
S: 500.00
S: </balance:notificationThreshold>
S: </balance:balance>
S: <balance:balance name="BAR">
S: <balance:currency>USD</balance:currency>
S: <balance:balanceAvailable>
S: 400.00
S: </balance:balanceAvailable>
S: <balance:creditLine>500.00</balance:creditLine>
S: <balance:cashBalance>-100.00</balance:cashBalance>
S: <balance:executionLimit>-300.00</balance:executionLimit>
S: <balance:notificationThreshold>
S: 600.00
S: </balance:notificationThreshold>
S: </balance:balance>
S: <balance:balance name="BAZ">
S: <balance:currency>EUR</balance:currency>
S: <balance:balanceAvailable>
S: 1000.00
S: </balance:balanceAvailable>
S: <balance:creditLine>200.00</balance:creditLine>
S: <balance:cashBalance>800.00</balance:cashBalance>
S: <balance:executionLimit>-200.00</balance:executionLimit>
S: <balance:notificationThreshold>
S: 300.00
S: </balance:notificationThreshold>
S: </balance:balance>
S: </balance:infData>
S: </resData>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
4.1.3. EPP <transfer> Command
Transfer semantics do not apply to balance objects, so there is no
mapping defined for the EPP <transfer> command.
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4.2. EPP Transform Commands
EPP provides five commands to transform objects: <create> to create
an instance of an object, <delete> to delete an instance of an
object, <renew> to extend the validity period of an object,
<transfer> to manage object sponsorship changes, and <update> to
change information associated with an object.
4.2.1. EPP <create> Command
Create semantics do not apply to balance objects, so there is no
mapping defined for the EPP <create> command.
4.2.2. EPP <delete> Command
Delete semantics do not apply to balance objects, so there is no
mapping defined for the EPP <delete> command.
4.2.3. EPP <renew> Command
Renew semantics do not apply to balance objects, so there is no
mapping defined for the EPP <renew> command.
4.2.4. EPP <transfer> Command
Transfer semantics do not apply to balance objects, so there is no
mapping defined for the EPP <transfer> command.
4.2.5. EPP <update> Command
Update semantics do not apply to balance objects, so there is no
mapping defined for the EPP <update> command.
5. Formal Syntax
The EPP Balance Mapping schema is presented here.
The formal syntax shown here is a complete XML Schema representation
of the object mapping suitable for automated validation of EPP XML
instances. The <CODE BEGINS> and <CODE ENDS> tags are not part of
the XML Schema; they are used to note the beginning and ending of the
XML Schema for URI registration purposes.
5.1. Balance Mapping Schema
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<CODE BEGINS>
<?xml version="1.0" encoding="UTF-8"?>
<schema
xmlns="http://www.w3.org/2001/XMLSchema"
xmlns:balance="urn:ietf:params:xml:ns:epp:balance-0.4"
targetNamespace="urn:ietf:params:xml:ns:epp:balance-0.4"
elementFormDefault="qualified">
<annotation>
<documentation>
Extensible Provisioning Protocol v1.0
Balance mapping.
</documentation>
</annotation>
<!--
Child elements found in EPP commands.
-->
<!-- Empty balance:info command element -->
<element name="info"/>
<!--
Child response elements.
-->
<element name="infData" type="balance:infDataType"/>
<!--Child elements of the balance:infData element -->
<complexType name="infDataType">
<sequence>
<element
name="balance"
type="balance:balanceType"
minOccurs="1"
maxOccurs="unbounded"/>
</sequence>
</complexType>
<!-- Child elements of the balance:balance element -->
<complexType name="balanceType">
<sequence>
<element name="currency" type="balance:currencyType"/>
<element
name="cashBalanceByCurrency"
type="balance:cashBalanceByCurrencyType"
minOccurs="0"
maxOccurs="unbounded"/>
<element
name="balanceAvailable"
type="balance:currencyValueType"/>
<element name="creditLine" type="balance:currencyValueType"/>
<element name="cashBalance" type="balance:currencyValueType"/>
<element
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name="executionLimit"
type="balance:limitBalanceType"
minOccurs="0"
default="0.00"/>
<element
name="notificationThreshold"
type="balance:limitBalanceType"
minOccurs="0"/>
</sequence>
<attribute name="name" use="optional">
<simpleType>
<restriction base="token"/>
</simpleType>
</attribute>
</complexType>
<simpleType name="currencyType">
<restriction base="string">
<pattern value="[A-Z]{3}"/>
</restriction>
</simpleType>
<simpleType name="currencyValueType">
<restriction base="decimal">
<fractionDigits value="2"/>
</restriction>
</simpleType>
<simpleType name="limitBasedOnType">
<restriction base="token">
<enumeration value="balanceAvailable"/>
<enumeration value="cashBalance"/>
</restriction>
</simpleType>
<complexType name="limitBalanceType">
<simpleContent>
<extension base="balance:currencyValueType">
<attribute
name="basedOn"
type="balance:limitBasedOnType"
default="balanceAvailable"/>
</extension>
</simpleContent>
</complexType>
<complexType name="cashBalanceByCurrencyType">
<simpleContent>
<extension base="balance:currencyValueType">
<attribute name="cashCurrency" use="required">
<simpleType>
<restriction base="string">
<pattern value="[A-Z]{3}"/>
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</restriction>
</simpleType>
</attribute>
<attribute
name="amount"
use="required"
type="balance:currencyValueType"/>
<attribute name="rate" use="required">
<simpleType>
<restriction base="decimal">
<fractionDigits value="50"/>
</restriction>
</simpleType>
</attribute>
</extension>
</simpleContent>
</complexType>
</schema>
<CODE ENDS>
6. IANA Considerations
6.1. XML Namespace
This document uses URNs to describe XML namespaces and XML schemas
conforming to a registry mechanism described in [RFC3688]. The
following URI assignment has been made by IANA:
Registration request for the balance namespace:
URI: urn:ietf:params:xml:ns:epp:balance-0.4
Registrant Contact: IESG
XML: None. Namespace URIs do not represent an XML specification.
Registration request for the balance XML Schema:
URI: urn:ietf:params:xml:schema:epp:balance-0.4
Registrant Contact: IESG
XML: See the formal syntax in Section 5.1.
6.2. EPP Extension Registry
The EPP extension described in this document has been registered by
IANA in the "Extensions for the Extensible Provisioning Protocol
(EPP)" registry described in [RFC7451]. The details of the
registration are as follows:
Name of Extension: "Balance Mapping for the Extensible Provisioning
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Protocol (EPP)"
Document Status: Standards Track
Reference: (insert reference to RFC version of this document)
Registrant Name and Email Address: IESG, <iesg@ietf.org>
TLDs: Any
IPR Disclosure: None
Status: Active
Notes: None
7. Security Considerations
The mapping extensions described in this document do not provide any
security services beyond those described by EPP [RFC5730] and
protocol layers used by EPP. The security considerations described
in these other specifications apply to this specification as well.
Financial information is confidential information for a client, so
the server MUST have access control restrictions in place to limit
access to financial information of the currently logged-in client.
8. Acknowledgements
The authors wish to thank the following persons for their feedback
and suggestions: Barbara Bellis and Margaux de Jans
9. References
9.1. Normative References
[ISO4217_2015]
ISO, "Codes for the representation of currencies",
ISO 4217:2015, August 2015,
<https://www.iso.org/standard/64758.html>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC5730] Hollenbeck, S., "Extensible Provisioning Protocol (EPP)",
STD 69, RFC 5730, DOI 10.17487/RFC5730, August 2009,
<https://www.rfc-editor.org/info/rfc5730>.
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[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
9.2. Informative References
[RFC7451] Hollenbeck, S., "Extension Registry for the Extensible
Provisioning Protocol", RFC 7451, DOI 10.17487/RFC7451,
February 2015, <https://www.rfc-editor.org/info/rfc7451>.
Appendix A. Change History
A.1. Change from 00 to REGEXT 00
1. Changed to regext working group draft by changing draft-gould-
regext-balance to draft-ietf-regext-balance.
A.2. Change from REGEXT 00 to REGEXT 01
1. Added Werner Staub from CORE as co-editor.
2. Changed the XML namespace from
"urn:ietf:params:xml:ns:epp:balance-0.1" to
"urn:ietf:params:xml:ns:epp:balance-0.3" and the XML schema from
"urn:ietf:params:xml:schema:epp:balance-0.1" to
"urn:ietf:params:xml:schema:epp:balance-0.3", based on the
needed XML schema changes.
3. Updated the XML schema and the example XML.
4. Updated the info response elements and re-ordered to match the
equation order.
5. Added a sub-section in the "Object Attributes" section for each
of the Balance Mapping elements / variables. The sub-sections
are referenced in defining the info response elements.
6. Changed the equation from Available Credit(AC) = Credit Limit
(CL) - Balance (B) to Balance (B) = Credit Limit (CL) + Cash
Balance (CB).
7. Added the definition of the Execution Limit (EL).
8. Changed the Credit Threshold to Notification Threshold.
9. Added ", inclusive of the fees and taxes" for the debits and
credits of the Cash Balance.
10. Added a reference to Section 4.1 "XML Schema" in the XML Schema
IANA registration based on feedback from IANA.
A.3. Change from REGEXT 01 to REGEXT 02
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1. Changed the XML namespace from
"urn:ietf:params:xml:ns:epp:balance-0.2" to
"urn:ietf:params:xml:ns:epp:balance-0.3" and the XML schema from
"urn:ietf:params:xml:schema:epp:balance-0.2" to
"urn:ietf:params:xml:schema:epp:balance-0.3", based on the needed
XML schema changes.
2. Changed Balance (B) to Balance Available (BA) in the text and
equations.
3. Changed the equation from Balance (B) = Credit Line (CL) + Cash
Balance (CB) to Balance Available (BA) = Credit Line (CL) + Cash
Balance (CB).
4. Updated the XML element tag from balance:balance to
balance:balanceAvailable across all text, examples, and the XML
schema.
5. Added "basedOn" attribute to the "executionLimit" and
"notificationThreshold" elements with a default value of
"balanceAvailable".
6. Added support for multi-currency accounts with the optional
cashBalanceByCurrency elements
A.4. Change from REGEXT 02 to REGEXT 03
1. Added Dimitrios Melissovas from Verisign as co-editor.
2. Changed the XML namespace from
"urn:ietf:params:xml:ns:epp:balance-0.3" to
"urn:ietf:params:xml:ns:epp:balance-0.4" and the XML schema from
"urn:ietf:params:xml:schema:epp:balance-0.3" to
"urn:ietf:params:xml:schema:epp:balance-0.4", based on the needed
XML schema changes.
3. Added support for multiple Balance accounts in Info and Poll
responses, with OPTIONAL "name" attribute for Balances based on
feedback from Barbara Bellis at Nominet.
4. Reworked definitions of "Currency" which are now children of
"Balance" objects.
5. Reworked "Different Conventions for Expressing Balances" section
under "Object Attributes" into "Balance", and added description
to support multiple Balance accounts.
6. Renamed references of "provider" to "server" and references of
"customer" to "client" throughout the document
Authors' Addresses
James Gould
VeriSign, Inc.
12061 Bluemont Way
Reston, VA 20190
United States of America
Email: jgould@verisign.com
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URI: http://www.verisign.com
Werner Staub
CORE
Email: werner.staub@corenic.org
URI: https://corenic.org
Dimitrios Melissovas
VeriSign, Inc.
12061 Bluemont Way
Reston, VA 20190
United States of America
Email: dmelissovas@verisign.com
URI: http://www.verisign.com
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