It is essential that you know all your passport and visa requirements and have obtained these before you travel. For travel to most countries a full British Passport is required valid for at least 6 months after you've returned to the UK.. However, as passport validity can vary from country to country (and is also subject to change), we recommend that you contact the relevant Embassy for the country you propose to visit for current information on passport validity requirements.
The United Kingdom Passport Service publishes a website which assists both new and existing passport holders who are British nationals resident in the UK