A wagering requirement is the number of times you must stake a bonus before its winnings can be withdrawn. A £10 bonus with 10x wagering means £100 of stakes, the playthrough, before the balance becomes withdrawable cash.
Since 19 January 2026, wagering requirements on casino bonuses from GB-licensed operators are capped at 10x. Before that, much higher multiples were common, and they often made the bonus close to worthless in practice.
Wagering has a cost because each pound staked carries the house edge. Illustrative example: £100 of playthrough on a 96% RTP slot has an expected loss of £4, so a £10 bonus is worth about £6 on average after wagering, before other terms. Game weighting can make the real figure higher, and a max bet rule limits how you can play it off.
Read the terms before accepting any bonus; you can usually decline one. See bonus rules.