In general, visit visas are valid for 6 month but they may be issued for longer, for 1, 2, 5 or even 10 years. However, those with longer term visas can still only stay in the UK for six months at any one time, other than Academic Visitors and parents of children at school as outlined above. Longer term visas are generally issued to frequent travelers.
Find more information directly at:
United Kingdom Embassy
Source & Copyright: The source of the above visa and immigration information and copyright owner is: Foreign & Commonwealth Office of UK – URL: https://www.gov.uk/government/organisations/foreign-commonwealth-office
Country : United Kingdom