Category B3 meaning in slots

What Category B3 means

Category B3 is a subtype of Category B in the British gaming machine categories. The Gambling Commission sets its maximum stake at £2 and its maximum prize at £500, the same headline limits as Category B2. The difference is where it can go: B3 is allowed in adult gaming centres and bingo halls, B2 is not.

On the high street, a B3 is usually a reel-based slot game in a cabinet, often with several games to choose from. In the glossary it sits between the casino-only Category B1 and the £1-stake Category C fruit machine.

Category B3 vs B3A and B4

B3A machines must say “THIS IS A LOTTERY MACHINE” and a club can have only one of them. B4 is the club-friendly option with a lower £400 top prize. The club rules are set out under club machine permits.

The 20% rule for B3 machines in arcades and bingo halls

Since 13 July 2011, an adult gaming centre or bingo hall may make Category B3 and B4 machines up to 20% of the total gaming machines available, with any number of Category C and D machines alongside. That rule was set by SI 2011/1710 (opens in a new tab) and still appears in section 172 of the Gambling Act 2005 (opens in a new tab). Licences granted before 13 July 2011 may keep four (AGCs) or eight (bingo) B3 or B4 machines, or 20%, whichever is greater.

Worked example: an AGC with 40 gaming machines can have up to 8 in Category B3 or B4 (20% of 40). The other 32 must be Category C or D. To add a ninth B3, it would need to grow to 45 machines in total.

On 16 May 2024 the government announced a move to a 2:1 ratio (two Category B machines for each C or D machine) for AGCs and bingo halls. As at 21 October 2026 that change has not been brought into force, so the 20% cap still applies.

How a Category B3 slot machine works

1. Put in cash or a ticket; direct debit card payments into machines remain restricted.
2. Pick a game and a stake of up to £2.
3. Start each game yourself; the RNG decides the result.
4. Wins up to £500 go to your credit meter.
5. Collect as a ticket, coins or a payment from staff.

A B3 must show a theoretical target return to player and be tested by an independent test house approved by the Commission, as its B3 gaming machines page (opens in a new tab) explains. No minimum return is set, so the label is the only way to compare.

Worked example: B3 costs per hour of play

Take a B3 with an illustrative target return of 90%. At £1 a game and 300 games, you would stake £300 and lose £30 on average; at the £2 maximum, the same 300 games stake £600 with an average loss of £60. That average assumes you replay winnings, which most people do. The same method works for any machine, as how much a slot costs per hour shows.

Where to play: B3 venues and online casinos

To play a B3 you need an 18+ venue such as an adult gaming centre or a bingo hall. Our partner casinos are online only. At Coral Casino, new players aged 18+ who bet £10 on slots get 100 free spins, valued at 10p each on selected games; accept them within 48 hours, use them within 7 days, and keep winnings without wagering. Certain deposit types don’t count.

Ladbrokes Casino gives new customers 18+ up to 500 free spins for playing £10 on slots: 50 a day for 10 days at 10p each, claimed by 23:59 daily, no wagering. Coral and Ladbrokes have the same operator, so check whether you can hold both accounts. Terms apply.

18+. Gambling should be entertainment that costs money, not a way to make it. Decide a budget before you play: plan a slot budget. Free, confidential help: National Gambling Helpline 0808 8020 133.