Why do I need to share my foreign bank account details?

In the tax filing instructions issued by the Portuguese Tax Authority (Autoridade Tributária e Aduaneira), Portuguese tax residents are required to report any deposit or security accounts held with any non-Portuguese financial institution.

Your foreign bank account information will be reported in Section 11 of your Portugal tax return.

For reference, you can find this on page 196 of this document.

English Translation:

Section 11 - DEPOSIT OR SECURITIES ACCOUNTS OPENED WITH A NON-RESIDENT FINANCIAL INSTITUTION IN PORTUGUESE TERRITORY OR WITH A BRANCH LOCATED OUTSIDE THE PORTUGUESE TERRITORY OF A RESIDENT FINANCIAL INSTITUTION

The purpose of this table is to identify deposit or security accounts opened at a non-resident financial institution in Portuguese territory or at a branch located outside the Portuguese territory of a resident financial institution, in the name of the holder identified in field 03 of Table 3A, or of which he is the beneficiary or is authorized to operate, in accordance with the provisions of paragraphs 8 and 9 of Article 63-A of the General Tax Law.

These accounts must be identified using the following elements:

• IBAN - International Bank Account Number (maximum 34 characters);
• BIC - Bank Identifier Code (maximum 11 characters).

If the accounts cannot be identified by IBAN or BIC, the respective account number must be identified.