Circular Letter No. CC/2025/00000009: Rules for the Use of the Unique Identifier for Payment Accounts Domiciled with Payment Service Providers Established in Portugal (IBAN PT)

Circular Letter No. CC/2025/00000009
Sent to:
Credit Institutions, Financial Companies, Payment Institutions, and Electronic Money Institutions.
Mod. 99999924/T – 01/14
Subject: Rules for the use of the unique identifier of payment accounts domiciled with payment service providers established in Portugal (“IBAN PT”)

1. Background
   The International Bank Account Number (IBAN) is a standardized payment account number structure, established as an international standard in 1997 with the publication of ISO 13616 by the International Organization for Standardization (ISO). The IBAN is constructed from the BBAN (Basic Bank Account Number) adopted in each country, preceded by the respective country code and two control digits. In the particular case of payment accounts domiciled in Portugal, the IBAN is composed of the former NIB (Bank Identification Number), which corresponds to the Portuguese BBAN, preceded by the country code “PT” and two control digits, which, in the Portuguese case, are always “50”. With the publication of Regulation (EU) No 260/2012 of the European Parliament and of the Council of 14 March 2012 establishing technical and business requirements for credit transfers and direct debits in euros (SEPA Regulation), the IBAN became enshrined, for the purpose of executing direct debits and SEPA transfers, as the identifier of payment accounts opened with a Payment Service Provider (PSP) established in the European Union. In this context, the identification of national payment accounts and the correct routing of transfers and direct debits depends on the definition of the national BBAN and, consequently, on the IBAN of which it is an integral part.

2. Object
   This Circular Letter aims to establish the structure and rules for the use of the unique identifier of payment accounts domiciled with payment service providers established in Portugal (“IBAN PT”), and to clarify which entities are authorized to assign national BBAN and IBAN to payment accounts.

3. Definitions
   The definitions contained in Regulation (EU) No 260/2012 of the European Parliament and of the Council of 14 March 2012 establishing technical and business requirements for credit transfers and direct debits in euros and amending Regulation (EC) No 924/2009 (SEPA Regulation), and in the Legal Regime of Payment Services and Electronic Money, approved in annex to Decree-Law No. 91/2018 of 12 November, apply within the scope of this Circular Letter.

Mod. 99999924/T – 01/14

4. Unique payment account identifier
   The unique identifier of a payment account domiciled with payment service providers established in Portugal (the IBAN PT) is based on the definition in ISO 13616 - International Bank Account Number (IBAN).
   4.1. The IBAN PT is composed of 25 alphanumeric characters corresponding to:
   a) the country code (PT); b) two control digits, calculated in accordance with the following letter b); and c) the Portuguese Basic Bank Account Number (BBAN) (Bank Identification Number - NIB).

Description Length Type Positions
IBAN PT
Country Code 2 Alphabetic 1-2
IBAN Control Digits 2 Numeric 3-4
NIB
Financial Agent Code 4 Numeric 5-8
Reference assigned by the PSP 4 Numeric 9-12
Account Number 11 Numeric 13-23
NIB Control Digits 2 Numeric 24-25
Total 25 Alphanumeric

4.2. The fields of the IBAN PT assume the following description:
a) Country Code - The country code of the IBAN PT is defined in accordance with ISO 3166 (3166-1 alpha-2 code). Based on this standard, the first two positions of the Portuguese IBAN are filled with the expression “PT”; b) IBAN Control Digits - The two control digits of the IBAN PT are calculated in accordance with ISO/IEC 7064, based on the MOD 97-10 algorithm. Regarding the IBAN PT, the control digits always correspond to “50”; c) Financial Agent Code - Corresponds to the financial agent code assigned by Banco de Portugal, which unequivocally identifies the payment service provider where the account is domiciled; d) Reference assigned by the PSP - Is a reference managed by the payment service provider that can be used to identify the type of payment account, the agency/counter where it is domiciled, or for any other internal classification; e) Account Number - Is the numeric identifier assigned by the payment service provider to its customer's payment account;

Mod. 99999924/T – 01/14

f) NIB Control Digits - The two control digits of the NIB are calculated in accordance with ISO/IEC 7064, based on the MOD 97-10 algorithm.

5. Entities authorized to assign IBAN PT to payment accounts
   5.1. The following payment service providers may assign IBAN PT to identify payment accounts domiciled with them:
   a) Credit institutions with headquarters in Portugal; b) Branches of credit institutions with headquarters outside Portugal, legally authorized to conduct business in Portugal; c) Payment institutions with headquarters in Portugal; d) Branches of payment institutions with headquarters outside Portugal, legally authorized to conduct business in Portugal; e) Electronic money institutions with headquarters in Portugal; f) Branches of electronic money institutions with headquarters outside Portugal, legally authorized to conduct business in Portugal; g) Financial companies with headquarters in Portugal whose object includes the exercise of this activity, in accordance with applicable legal and regulatory standards; h) Postal giro institutions authorized by national law to provide payment services in Portugal; i) The State, the Autonomous Regions, and the services and bodies of the direct and indirect state administration, when they do not act in the exercise of public authority powers; j) Banco de Portugal, when it does not act in the capacity of monetary authority or in the exercise of public authority powers.

5.2. The entities identified in the previous point may only issue IBAN PT from the moment they effectively commence their activity in Portugal.
5.3. Entities not established in Portugal are prohibited from assigning IBAN PT.

6. IBAN registry and contact point
   6.1. Banco de Portugal ensures, through the Society for Worldwide Interbank Financial Telecommunication SCRL (SWIFT), the entity designated by the ISO Technical Management Board to act as the Registration Authority for ISO 13616, the permanent update of the IBAN Registry.
   6.2. Banco de Portugal is the contact point in Portugal for matters related to the assignment of IBAN-PT, notably regarding communications with the recipients of this Circular Letter, for the purpose of complying with what is established therein.