As of 2023, UK citizens do not need a visa to enter Portugal for short-term stays of up to 90 days within any 180-day period. This is because the UK, despite leaving the European Union, remains on the list of "visa-exempt" third countries for the Schengen Area. This 90-day allowance covers tourism, visiting friends or family, and short-term business trips. However, there are several post-Brexit rules you must follow: your passport must be less than 10 years old on the day you enter and must be valid for at least three months after the day you plan to leave. You should also be prepared to show a return or onward ticket and proof of sufficient funds for your stay at the border. While no visa is currently required, travelers should be aware that the European Union is preparing to launch the ETIAS (European Travel Information and Authorisation System). Although it was delayed past 2023, once it is active (expected in late 2025 or 2026), UK citizens will need to apply for this electronic authorization online before traveling to Portugal. It is a quick process and is not a "visa," but rather a security pre-screening similar to the US ESTA. For now, a valid UK passport is all that is required for a standard holiday in the Algarve or Lisbon.