Montenegro Visa Requirements
British citizens don’t need a visa to enter Montenegro if travelling for tourism up to 90 days. The Montenegrin law considers ‘stays of 90 days’ as 90 days in total in a 180-day period, counted from the first entry date.
Make sure the border police put an entry stamp in your passport to avoid problems related to confirming the length of your stay in the country.
Passport Validity for Montenegro Travel
Your passport should be issued less than ten years before the date you enter the country and valid for at least three months after the day you plan to leave.
For further information, please check with the embassy.