British holidaymakers jetting off to Spain, Greece and many other countries must follow a post-Brexit rule - or be refused boarding at the airport. While the prospect of an overseas getaway is thrilling, it's important for travellers to be aware of all requirements before setting off.

This has become especially vital following Brexit, which has introduced new regulations in recent years. Prior to Britain's departure from the European Union (EU), UK passport holders could visit the Schengen Area without requiring passport stamps and weren't subject to any time limits on their stays.

However, British visitors are now limited to a maximum of 90 days during any 180-day period. To assist with this, an application called Schengen Simple has been developed.

• New passport rule from Wednesday means UK citizens 'could be refused boarding'


• Passport holders told to take action or face airport queues that 'could last hours'

George Cremer, founder of Schengen Simple, said: "We built a travel app that handles the 90/180 calculation for exactly this reason. The tricky part most people miss is that it's a rolling 180-day window, not a fixed calendar period.

"So someone who did a long summer trip to Spain might unknowingly be restricted on a winter break months later. The European Commission has its own calculator, but it only looks backwards.

"It tells you how many days you've used, not how many you have left for a future trip. That's the gap we fill. Users enter past and upcoming travel and can see exactly how long they can stay without risking an overstay."

The Foreign Office's guidance for all Schengen nations warns: "If you overstay the 90-day visa-free limit, you may be banned from entering Schengen countries for up to 3 years."

The Schengen area consists of: Austria, Belgium, Bulgaria, Czechia, Croatia, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, Liechtenstein, Luxembourg, Malta, Norway, The Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden and Switzerland.