TUI has issued a warning to British passengers about their passports, travel insurance and documents.
The UK's departure from the EU now means that Brits heading to Europe as tourists will be treated as any other non-EU nation. UK citizens making short trips to the EU, EEA or Switzerland can stay without a visa for up to 90 days in any 180-day period.
However, the Government has said visitors to the UK may be refused entry if it is “clear from their travel history they are seeking to remain in the UK for extended periods or making the UK their home via repeated visits”.