The Town and Country Planning (Use Classes) Order 1987 (as amended) puts uses of land and buildings into various categories known as 'Use Classes' which are detailed below.

The current Use Classes were last updated on 1 September 2020. Generally for any applications, the Use Classes in effect when the application was submitted will be used to determine it. There are other specific areas of legislation that will allow use of Use Classes as they were at a specific point in time.

Revoked Use Classes - Old Use Classes are included here for reference and use in specific situations where they remain valid.

Class A was revoked from 1 September 2020. Class A 1/2/3 were effectively replaced with Use Class E(a,b,c). A4/5 uses were not covered by Use Class E and became defined as 'Sui Generis'
A1 Shops - Shops, retail warehouses, hairdressers, undertakers, travel and ticket agencies, post offices, pet shops, sandwich bars, showrooms, domestic hire shops, dry cleaners, funeral directors and internet cafes
A2 Financial and professional services - Financial services such as banks and building societies, professional services (other than health and medical services) and including estate and employment agencies. It does not include betting offices or pay day loan shops - these are now classed as "sui generis" uses (see below)
A3 Restaurants and cafés - For the sale of food and drink for consumption on the premises - restaurants, snack bars and cafes
A4 Drinking establishments - Public houses, wine bars or other drinking establishments (but not night clubs) including drinking establishments with expanded food provision
A5 Hot food takeaways - For the sale of hot food for consumption off the premises.

B1 Business was revoked from 1 September 2020. It is effectively replaced with the new Class E(g).
B1 Business - Uses which can be carried out in a residential area without detriment to its amenity. This class was formed of three parts:
B1(a) Offices - Other than a use within Class A2 (see above)
B1(b) Research and development of products or processes
B1(c) Industrial processes
Use Classes B2 and B8 remain valid (see 'Current Use Classes' above).
Use Classes B3 (revoked in 1992), and B4 to B7 (revoked in 1995) were used to call out specific industrial uses.

Class D was revoked from 1 September 2020. D1 was split out and replaced by the new Classes E(e-f) and F1. D2 was split out and replaced by the new Classes E(d) and F2(c-d) as well as several newly defined 'Sui Generis' uses.
D1 Non-residential institutions - Clinics, health centres, crèches, day nurseries, day centres, schools, art galleries (other than for sale or hire), museums, libraries, halls, places of worship, church halls, law court. Non-residential education and training centres
D2 Assembly and leisure - Cinemas, music and concert halls, bingo and dance halls (but not night clubs), swimming baths, skating rinks, gymnasiums or area for indoor or outdoor sports and recreations (except for motor sports, or where firearms are used).

However, it is advised that you confirm the specifics of any of these potential situations with the relevant Local Planning Authority.