Check the check digit of Portuguese NIF, NISS, NIB and IBAN numbers, see the taxpayer type and generate test numbers.
The NIF (Número de Identificação Fiscal) has 9 digits and the last one is a check digit computed with modulus 11: the first 8 digits are multiplied by 9, 8, 7, 6, 5, 4, 3 and 2, added up, and the remainder of the division by 11 sets the ninth. A remainder of 0 or 1 gives 0, anything else gives 11 minus the remainder. For 123456789 the sum is 156, the remainder is 2 and the digit is 9. The first digit (or first two) tells who the holder is, according to the Portuguese Tax and Customs Authority (AT) manual: 1, 2 and 3 are individuals (range 3 was announced in 2019), 45 non-resident individuals with withholding tax, 5 legal entities, 6 public administration, 70 and 74 undivided estates, 71 non-resident entities, 72 funds, 77 and 78 ex officio assignments, 90 and 91 condominiums and irregular companies, 98 non-residents and 99 civil companies. Prefix 8 (sole trader) is obsolete. The NISS (Número de Identificação da Segurança Social) has 11 digits. Public validators multiply the first 10 by 29, 23, 19, 17, 13, 11, 7, 5, 3 and 2 and use 9 minus the sum's remainder by 10 as the last digit. I did not find that calculation in an official text, so treat it as a well-established convention. The NIB has 21 digits (bank, branch, account and 2 check digits) and follows ISO 7064 mod 97-10, per Banco de Portugal: read as one number it leaves remainder 1 when divided by 97. The IBAN is PT50 plus the NIB. Passing the check only says the number is well formed. To find out whether a VAT number is active, use the European Commission's VIES service.
Paste the code into your HTML and the tool shows up on your page, without J-Kit's navigation and ads. It still runs in the browser of whoever visits your site.
<iframe
src="https://jkit.tools/embed/en-US/portugal-nif-validator"
width="100%"
height="600"
style="border:0"
loading="lazy"
title="Portugal NIF, NISS and NIB Validator and Generator"
></iframe>These references help contextualize formulas, standards, APIs and limitations used on this page. They do not replace professional validation when a result has legal, financial, medical or operational impact.
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.
Valid NIF structure
This checks structure and arithmetic only. It does not prove the number was issued to anyone, or that the account exists.