Tax declaration news in Portugal

From 1 January 2026 the amendment to the VAT periodicity regime shifts the onus from the Tax and Customs Authority to the taxpayer: rather than receiving an official reclassification, taxpayers must now submit a formal declaration to request a change of periodicity. The declaration should identify the taxpayer (tax identification number and contact details), state the current and requested VAT periodicity classification, give the intended effective date and the legal or factual reasons for the change (for example a change in turnover, accounting regime or business structure), and attach any supporting documents required by the Authority.

In practice the declaration is normally submitted electronically via the Authority’s online portal and must be signed with the appropriate digital signature or authentication method. Before filing, reconcile turnover figures and previous VAT returns so the requested periodicity is consistent with statutory thresholds; indicate whether the change is temporary or permanent; and keep a copy of the submission receipt. Late, incomplete or absent declarations can lead to the Authority maintaining the previous classification, administrative penalties or cash‑flow disruption from an unexpected reporting frequency. For most taxpayers — and especially for expats or businesses undergoing structural change — it is advisable to consult an accountant or tax adviser to check eligibility, prepare supporting evidence and confirm the correct form fields and deadlines on the Authority’s website.