Since launching in October 2025, the European Union's Entry-Exit System (EES) has proved controversial. It is supposed to make the process of entering and leaving the EU simpler for Brits, but there have been reports of long airport queues and confusion caused by its implementation.

While the EES won't go fully live until April 10, with many countries still inconsistent about whether they are using it or not, it appears that it's already starting to catch out holidaymakers who are confused by a certain EU rule.

Digital nomad George Cremer, a software developer who launched an app to help British and other non-EU nationals navigate the new rules, said that the 90-day rule is already starting to catch people out. "Before EES, many miscalculations went unnoticed because border officials had to manually check passport stamps.

"Now every entry and exit is tracked digitally, and the system flags overstays automatically. So that 4,000 figure certainly includes a large number of people who genuinely believed they were compliant, some of whom have been in touch with us seeking guidance."

The number is based on data from eu-LISA, the EU agency responsible for managing the border control systems. George's app, Schengen Simple, helps people ensure they are following the 90/180-day rule, which limits non-EU nationals such as Brits to 90 days of visa-free travel within the Schengen Area over a rolling 180-day period.

While the 90/180-day rule sounds simple, George told Majorca Daily News that there were three common mistakes that could catch people out. The main issue is that people don't realise it's a rolling window. He explained: “Most people think the 90 days work like a visa stamp: use up your days, leave, and the clock resets. It doesn’t.

"The 90/180 rule uses a rolling window, so every single day, the system looks back 180 days and counts how many of those you spent in the Schengen Area. A week in Portugal in January quietly eats into your summer allowance."

He went on to explain that your days don't reset if you leave and re-enter, the window keeps rolling. While some people who live overseas do 'visa hopping' where you can leave for a few days and the period resets, this doesn't work for the EU.

George also said that some people get caught out as they think each country tracks separately. "All 29 Schengen countries share one 90-day pool. A weekend in Paris and a month in Spain are counted together." He also reiterated that the rule is not 90-days per half year, as some assume the 180-days is a January to June/July to December split. However, it's not. The 180 days count backwards from each individual day.

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He also issued a warning for the upcoming busy travelseason: "The other thing people miss is forward planning. With Easter and summer both approaching, travellers need to think about how their trips interact.

"Using up days over Easter could leave you short for a holiday you've already booked in July. We built Schengen Simple to work both ways, factoring in future plans so people can see their real allowance before they commit to a booking."

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