evidence: UK travellers used to be able to carry up to nine months from an old passport over on to a new one. But post-Brexit, EU countries will not accept passports issued more than 10 years ago. [...] Since the UK left the EU, travellers heading to all countries within the bloc - and including Iceland, Norway, Lichtenstein and Switzerland, but not Ireland - must have a passport which was issued less than 10 years before their departure date. [...] However, if a UK passport was issued before September 2018, it could be valid for up to 10 years and nine months.