A cap on how much you can withdraw from bonus winnings, regardless of how much you actually won. A £50 bonus with a 10x cashout cap means £500 is the most you can take, and anything above that is forfeited.
How it works
You take a bonus, meet the wagering requirement, and finish with more than the cap allows. The operator pays the cap and removes the rest. This is legal and disclosed, and it is the single most common reason a player feels cheated by a bonus they technically completed.
A 10x cap on a £50 bonus means £500 maximum. If you turned that bonus into £2,000, you receive £500.
Where you will meet it
Caps are standard on no-deposit bonuses and free spins with no deposit, which makes sense: the operator gave you something for nothing and limits its exposure. They are also common on cashback and reload offers.
Caps are much less common on straightforward welcome deposit matches, where you have put your own money at risk. If a deposit-match bonus has a cashout cap, that is a mark against the offer and we deduct for it.
How to find it before you play
Look in the bonus terms for "maximum cashout", "maximum withdrawal", "winnings cap" or a phrase like "winnings from this bonus are capped at". If the terms are silent on the point, the cap is probably the general bonus policy, which is worth reading once per operator.
The practical rule
On a no-deposit offer, assume there is a cap and treat the bonus as entertainment rather than as a route to a meaningful win. On a deposit offer, if you find a cap, weigh it against declining the bonus entirely. Your deposit without a bonus is real cash with no cap and no wagering.