A casino bonus gives you extra funds or free spins, usually in exchange for a deposit, and attaches conditions before any resulting money can be withdrawn. The main condition is the wagering requirement: the amount you must stake first, expressed as a multiple. In Great Britain, wagering requirements are capped at 10x from 19 January 2026.
This guide explains how these offers work and the maths behind them. It does not cover any particular operator’s offer, and offers change often; the terms at the site are what count.
The main types of offer
| Offer | How it usually works |
|---|---|
| Deposit match | The site adds bonus funds as a percentage of your deposit, up to a limit |
| Free spins | A set number of spins on named games at a fixed stake |
| No-deposit bonus | A small bonus or spins without a deposit, with tight conditions |
| Cashback | A share of losses returned, sometimes as cash, sometimes as bonus funds |
| Wager-free offers | Winnings paid as cash with no wagering, often with other limits |
Bonus funds are usually held separately from your own cash. The terms say which balance is used first and when bonus money becomes withdrawable.
Wagering requirements
A wagering requirement says how much you must stake before bonus funds, or winnings from them, can be withdrawn. It is stated as a multiple of something, usually the bonus, sometimes the bonus plus deposit, sometimes winnings from free spins. That base matters as much as the multiple.
The 10x cap
From 19 January 2026, GB-licensed operators cannot set wagering requirements above 10x on casino bonuses. From the same date, promotions that mix products, such as betting on football to receive slot spins, are banned. Our bonus rules page covers the detail.
The maths, illustrated
Wagering does not cost you the full amount you stake. It costs you the house edge on that amount, on average. Expected loss is total staked × (1 − RTP).
Take an illustrative £20 bonus with a 10x wagering requirement, played on slots with a 96% RTP:
- Wagering: 10 × £20 = £200 of stakes.
- Expected loss while wagering: £200 × 4% = £8.
- Expected value of the bonus: £20 − £8 = £12, before any other conditions.
Now compare higher multiples, which were allowed before the cap, using the same illustrative numbers:
| Wagering | Stakes required | Expected loss at 96% RTP | Bonus left on average |
|---|---|---|---|
| 10x | £200 | £8 | £12 |
| 25x | £500 | £20 | £0 |
| 35x | £700 | £28 | −£8 |
At 25x, the house edge is expected to consume the whole bonus. At 35x, the expected cost of wagering exceeds the bonus, so the offer has negative value on average. The cap makes bonuses less punishing, but it does not make them profit.
These are averages. Because slots are volatile, many players will lose the bonus well before completing the wagering, and a few will finish with more. Try your own figures in the RTP calculator.
Game weighting
Not every game counts fully towards wagering. Terms often say slots count 100% while other games count less or not at all. If a game counts 10%, a £1 stake only clears 10p of wagering, so you need ten times as many stakes to finish.
Some terms also exclude particular slots, such as jackpot games. Playing an excluded game may not count towards wagering, or may breach the terms.
Maximum bet rules
Most bonuses limit the stake per spin while bonus funds are in play. Breaking it, even once, can let the operator void the bonus and any winnings from it. This limit is separate from the legal stake limits on online slots in Great Britain, £5 per spin for players aged 25 and over and £2 for 18 to 24 year olds. The bonus limit is often lower.
Expiry
Bonuses and free spins expire. There is usually one deadline for using the spins or claiming the bonus, and another for completing the wagering. Unused bonus funds, and winnings still subject to wagering, are typically removed at expiry.
Other terms to look for
- Maximum win or conversion: a cap on how much bonus money can become cash.
- Withdrawal before completion: withdrawing your own deposit early may forfeit the bonus.
- Eligible payment methods: some methods may be excluded from offers.
- Free spin value: the stake each spin is played at, which sets what they are worth.
- Opt-in: you may need to choose the offer before depositing.
Why read the terms
The headline of an offer is a summary; the terms are the deal. Two offers that look identical can differ completely once you factor in what the wagering is based on, game weighting, stake limits, caps and expiry. Bonus terms are also where most disputes start, because a player believed the headline.
You do not have to take a bonus. Declining one means your deposit stays as cash, with no wagering, stake caps or expiry, and you can withdraw it whenever you like.
Bonuses and safer gambling
Bonuses are designed to encourage play. If you find yourself depositing to unlock an offer or playing longer to clear wagering you would not otherwise have done, stop. Deposit limits and other tools are covered in setting limits, and free support is listed on our safer gambling page.
The short version
- Bonuses add funds or spins but come with conditions before you can withdraw.
- Wagering requirements are capped at 10x in Great Britain from 19 January 2026; mixed-product offers are banned from the same date.
- Expected cost of wagering = total staked × (1 − RTP).
- At illustrative figures, 10x on a £20 bonus at 96% RTP costs about £8 on average.
- Watch game weighting, maximum bet rules, expiry and caps on winnings.
- A bonus does not turn gambling into a way to make money.
Questions people ask
What does 10x wagering mean?
It means you must stake ten times the bonus amount, or whatever amount the terms specify, before bonus funds or winnings can be withdrawn. A £10 bonus with 10x wagering requires £100 of stakes.
What is the maximum wagering requirement in Great Britain?
From 19 January 2026, wagering requirements on casino bonuses offered by GB-licensed operators are capped at 10 times. The same change banned promotions that mix gambling products, such as betting on sport to receive casino spins.
Are free spins offers really free?
The spins themselves cost nothing extra, but any winnings usually come as bonus funds with conditions such as wagering, expiry dates and limits on what can be withdrawn. Read the terms to see what you can actually keep.
Can I use a bonus to make money?
No. Wagering means more stakes go through games with a house edge, which eats into the bonus. A bonus can extend play, but the expected result of gambling is still a loss.
Next guide: How to Play Online Slots in Great Britain: A Plain Guide