The Dissolution and Calling of Parliament Act 2022 states that the maximum term of a Parliament is five years. The formal end of a Parliament is called dissolution.
The King has the legal power to dissolve Parliament. In practice, the King acts on advice of the Prime Minister, who can request a dissolution in order to allow a general election.
If Parliament has not been dissolved by the fifth anniversary of the day it first met, it will be automatically dissolved.
Parliament may be prorogued a few days before dissolution takes place. At prorogation, all parliamentary business ends but Parliament continues to exist until dissolution.
Dissolution triggers the start of the general election campaign. It also begins the pre-election period during which, by the convention, the Government doesn’t make major policy announcements or enter into significant commitments.
Polling takes place 25 working days after dissolution but Saturdays, Sundays, Christmas Eve, Christmas Day, Boxing Day, New Year's Day and the Scottish Bank Holiday on 2 January are not counted in calculating the 25 days.
When Parliament is dissolved, every seat in the House of Commons becomes vacant. You are no longer an MP and must not use this title. The House and IPSA issue detailed guidance before dissolution for MPs and their staff. The House's facilities are no longer available to you from 5pm on the day of dissolution.