How this works
A Portuguese IBAN has 25 characters: the PT prefix, two international check digits, and the 21-digit NIB (bank, branch, account number and two national check digits). The generator picks the fields — at random or with the bank you choose — and computes all four check digits with the same mod-97 (ISO 7064) formula banks use. The result passes any validator, but is purely fictitious.
- 1
Build the base NIB
Bank (4) + branch (4) + account number (11). You can fix the bank; the rest is random.
- 2
National check digits
Take bank+branch+account with "00" appended, take mod 97, then 98 minus the remainder, as two digits.
- 3
IBAN check digits
Move "PT00" to the end (P=25, T=29, 00), apply mod 97 to the whole, then 98 minus the remainder.
Frequently asked
Can these IBANs receive or send money?
No. They are fictitious numbers that only satisfy the maths of the Portuguese format. They are not tied to any real account, bank or person. They exist to fill fields in test environments, not to move money.
What is an IBAN generator for?
Anyone building payment, billing or accounting software needs well-formed IBANs to test forms, validations and SEPA integrations — without using real people’s bank details. Generating fictitious but structurally correct numbers avoids exposing real accounts during development.
How are the check digits computed?
There are two calculations. First the 2 national digits (at the end of the NIB): take bank+branch+account followed by "00", compute the remainder mod 97, then 98 minus that remainder. Then the 2 IBAN digits: move "PT00" to the end (P=25, T=29, 00), compute mod 97 of the whole, then 98 minus the remainder. This is the standard ISO 7064 algorithm.
Can I pick the bank?
Yes. You can leave everything random or fix the bank code (the first 4 digits), e.g. 0002, 0033 or 0010. The check digits are always recomputed so the IBAN passes any validator.
Does a formula-valid IBAN map to a real account?
Not necessarily. Passing mod-97 only means it is well-built. It may, by coincidence, match an existing account — hence the golden rule: use generated IBANs only for technical testing, never to pose as an account holder.
DISCLAIMER
The generated IBANs are fictitious and intended solely for software testing. They are tied to no real account and may, by coincidence, match an existing IBAN. Using an IBAN that was not assigned to you to receive payments, open services or identify yourself to third parties or the State is fraud and punishable by law. This is not financial advice.