Portugal NIF, NISS and NIB Validator and Generator

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Portuguese NIB vs IBAN how to calculate

Portuguese NIB and IBAN: difference and how to validate

In Portugal two names coexist for the same account: NIB, the national number, and IBAN, the international format. They carry the same information, and knowing the relation avoids typing errors in transfers. Paste either into the tool and it shows the other.

Structure and mod 97

The NIB has 21 digits, per Banco de Portugal: 4 for the financial agent code (the bank), 4 for the payment service provider reference (the branch), 11 for the account number and 2 check digits. The Portuguese IBAN has 25 characters: the country code PT, the IBAN check digits, which in Portugal are always 50, and the whole NIB. So an IBAN is PT50 followed by the NIB, and to get back to the NIB you just drop the first 4 characters.
The NIB check digits follow ISO/IEC 7064 mod 97-10. In practice, read the 21 digits as a single number: it must leave remainder 1 when divided by 97. To compute the two digits of an incomplete NIB, append 00 to the first 19 digits, find the remainder by 97 and use 98 minus that remainder, with 2 places. For NIB 0002 0123 1234 5678 9015 4 that gives 54, and for 0018 0000 4035 9330 0018 7 it gives 87. The same calculation applied to the IBAN order explains why the 50 is fixed.
The check detects almost every single-digit error and most swaps of neighbouring digits, but it does not say whether the account exists or whose it is: only the bank confirms. Today transfers and direct debits use the IBAN, per Banco de Portugal, and the NIB remains as part of the IBAN. When you ask someone in Portugal for an IBAN, always check the key with the tool before sending money, and use the IBAN generated here only in tests: it carries bank code 9999, which I chose because it matches no bank I know of.

Worked NIB and IBAN

Example NIB

Input: 0002 0123 1234 5678 9015 4
Expected output: NIB válido, IBAN PT50 0002 0123 1234 5678 9015 4

A public example Portuguese IBAN.

Another valid NIB

Input: 0018 0000 4035 9330 0018 7
Expected output: NIB válido, IBAN PT50 0018 0000 4035 9330 0018 7

Check 87.

Wrong check

Input: 0018 0000 4035 9330 0018 8
Expected output: Inválido, o certo termina em 87

One digit swapped at the end.

Only the first 19 digits

Input: 0002012312345678901
Expected output: Controlo 54

98 minus the remainder by 97.

Generator test IBAN

Input: 9999 0000 1234 5678 9012 2
Expected output: IBAN PT50 9999 0000 1234 5678 9012 2

Test bank code 9999.

Full tool FAQ

How does the NIF check digit work?

Each of the first 8 digits is multiplied by the weights 9, 8, 7, 6, 5, 4, 3, 2 and the products are added. The remainder of the division by 11 decides the ninth digit: 0 or 1 gives 0, and any other remainder r gives 11 minus r. For 204716624 the sum is 139, the remainder is 7 and the digit is 4.

What does the first digit of a NIF mean?

Does a NIF that passes validation really exist?

How does a Brazilian get a NIF in Portugal?

Are NIF, NIPC and número de contribuinte the same thing?

How is the NISS digit calculated?

What is the difference between NIB and IBAN?

Can I use the generated numbers on forms?

Does the tool validate the Cartão de Cidadão number?

Why do some NIFs start with 3 and with 8?

Frequently asked questions

Is the NIB still used?

As a standalone number, less and less: credit transfers and direct debits require the IBAN. But the NIB lives on inside the IBAN, which is PT50 plus its 21 digits.

Why does the Portuguese IBAN always start with PT50?

Banco de Portugal documents that the IBAN check digits are always 50 for Portuguese accounts. Since the NIB already satisfies mod 97, the IBAN closes with the same value in every case.

Can I use the generated IBAN to receive money?

No. It only passes format validations and leads to no account. Use it in form and import tests.

Next steps

Structure and mod 97

The NIB has 21 digits, per Banco de Portugal: 4 for the financial agent code (the bank), 4 for the payment service provider reference (the branch), 11 for the account number and 2 check digits. The Portuguese IBAN has 25 characters: the country code PT, the IBAN check digits, which in Portugal are always 50, and the whole NIB. So an IBAN is PT50 followed by the NIB, and to get back to the NIB you just drop the first 4 characters.

The NIB check digits follow ISO/IEC 7064 mod 97-10. In practice, read the 21 digits as a single number: it must leave remainder 1 when divided by 97. To compute the two digits of an incomplete NIB, append 00 to the first 19 digits, find the remainder by 97 and use 98 minus that remainder, with 2 places. For NIB 0002 0123 1234 5678 9015 4 that gives 54, and for 0018 0000 4035 9330 0018 7 it gives 87. The same calculation applied to the IBAN order explains why the 50 is fixed.

The check detects almost every single-digit error and most swaps of neighbouring digits, but it does not say whether the account exists or whose it is: only the bank confirms. Today transfers and direct debits use the IBAN, per Banco de Portugal, and the NIB remains as part of the IBAN. When you ask someone in Portugal for an IBAN, always check the key with the tool before sending money, and use the IBAN generated here only in tests: it carries bank code 9999, which I chose because it matches no bank I know of.

Worked NIB and IBAN

Example NIB

Input: 0002 0123 1234 5678 9015 4
Expected output: NIB válido, IBAN PT50 0002 0123 1234 5678 9015 4

A public example Portuguese IBAN.

Another valid NIB

Input: 0018 0000 4035 9330 0018 7
Expected output: NIB válido, IBAN PT50 0018 0000 4035 9330 0018 7

Check 87.

Wrong check

Input: 0018 0000 4035 9330 0018 8
Expected output: Inválido, o certo termina em 87

One digit swapped at the end.

Only the first 19 digits

Input: 0002012312345678901
Expected output: Controlo 54

98 minus the remainder by 97.

Generator test IBAN

Input: 9999 0000 1234 5678 9012 2
Expected output: IBAN PT50 9999 0000 1234 5678 9012 2

Test bank code 9999.

Full tool FAQ

How does the NIF check digit work?

What does the first digit of a NIF mean?

Does a NIF that passes validation really exist?

How does a Brazilian get a NIF in Portugal?

Are NIF, NIPC and número de contribuinte the same thing?

How is the NISS digit calculated?

What is the difference between NIB and IBAN?

Can I use the generated numbers on forms?

Does the tool validate the Cartão de Cidadão number?

Why do some NIFs start with 3 and with 8?

Frequently asked questions

Is the NIB still used?

As a standalone number, less and less: credit transfers and direct debits require the IBAN. But the NIB lives on inside the IBAN, which is PT50 plus its 21 digits.

Why does the Portuguese IBAN always start with PT50?

Banco de Portugal documents that the IBAN check digits are always 50 for Portuguese accounts. Since the NIB already satisfies mod 97, the IBAN closes with the same value in every case.

Can I use the generated IBAN to receive money?

No. It only passes format validations and leads to no account. Use it in form and import tests.