300% deposit bonus

300% deposit bonus: what the number means

A 300% deposit bonus adds three pounds of bonus for every pound you deposit. Put in £10 and you receive £30 of bonus, giving you £40 in total. Advertisers often phrase exactly the same deal as deposit £10, play with £40, which is easier to picture but hides the fact that £10 of the £40 is your own money.

Percentages above 100% sound striking, which is why they turn up in adverts. What they don’t tell you is the bonus cap, the wagering or the expiry, and those three lines decide almost all of the value. A 300% offer is a type of casino match bonus and follows the same rules: 18+ only, and the full terms apply.

Does any UK casino offer a 300% deposit bonus?

Not among the casinos we work with. Our partners’ offers, last checked on 5 October 2026, include two percentage matches: 10bet at 100% up to £25 and Casumo at 50% up to £100. The other three lead with spins. We won’t pretend otherwise to fit a search term.

A 300% rate at a UK-licensed casino would be unusual for the reasons explained below. Where you do see it, check the operator’s Gambling Commission account number on the public register, and confirm the wagering is within the 10x limit. Our guide on how to check a casino licence shows where to look.

The cap is the real headline on a 300% offer

Because the rate is so high, a 300% offer reaches its cap quickly, often on the smallest allowed deposit. After that, every extra pound is ordinary cash with no bonus attached. Divide the cap by three to see the deposit that fills it.

The last column shows what happens if you deposit £50 into each offer. With a £30 cap, the bonus works out at only 60% of that deposit, less than a straightforward 100% match on the same amount. Rate and cap must always be read together; our match percentage entry explains how the two interact.

300% bonus wagering before and after 19 January 2026

Until 2026, very high percentages were usually balanced by very high wagering. The Gambling Commission’s own example, given when it announced the change (opens in a new tab), was a £10 bonus with 50x wagering needing £500 of play. Since 19 January 2026, UK-licensed casinos have been limited to 10x the bonus by social responsibility code 5.1.1 (opens in a new tab).

Read the table from the casino’s side. At 35x or 50x, the house edge on the required staking was expected to recover more than the whole bonus, so a 300% headline cost the operator little. At 10x, the expected recovery is less than half the bonus. Our 10x vs 35x wagering comparison and the bonus rules timeline cover the change in more depth.

These are long-run averages on a slot with 96% RTP. Any one session can end well above or well below them, and many bonuses are used up before the wagering is finished.

Why big percentages and a 10x cap rarely meet

Put simply, the cap made generous percentages expensive. An operator offering 300% at 10x gives away far more expected value per customer than one offering 50% or 100% with a low cap. That is why UK-licensed casinos have tended to keep match rates modest, hold caps low, or move to free spins with a fixed value per spin.

Other costs point the same way. Remote gaming duty paid by operators rose from 21% to 40% of gaming profits on 1 April 2026, and the rules on financial vulnerability checks and marketing consent add more care to every new customer relationship. None of that is a cost to the player, but together these explain why triple-figure percentages have largely disappeared from UK-licensed sites. Our new casino bonuses page tracks how offers changed through 2026.

Reading a 300% offer’s terms line by line

Here is how each typical line in a large match offer should be read. The examples are illustrative, not taken from any one casino.

Our bonus terms guide takes each clause further, and how to spot unfair bonus terms explains which wording the Gambling Commission and CMA consider unacceptable.

How to weigh a 300% offer in six checks

1. Confirm the casino is licensed by the Gambling Commission and see who runs it.
2. Turn the headline into pounds: the bonus your deposit would actually bring, after the cap.
3. Multiply that bonus by the wagering figure to get the total staking required.
4. Compare the total staking with the time allowed and with how much you normally play.
5. Check the max bet, max win and eligible games, plus any excluded payment methods.
6. Ask whether you would make this deposit with no bonus at all; if the answer is no, leave it.

300% against the partner offers on a £10 deposit

A £10 deposit is where 300% offers look strongest, so it is the fairest place to compare. The table uses only our partners’ published terms.

At £10, the PlayOJO deal is the simplest to value: £8 of spins on a slot with 96.71% RTP returns about £7.70 on average, paid as cash. Our £10 deposit bonus page and the best bonus for £10 comparison go further.

UK safeguards that apply to any match bonus

• Your own money: you can withdraw your deposit balance at any time, even with a bonus active, under the principles that followed the CMA’s online gambling case (opens in a new tab).
• Clear terms: significant conditions must appear with the offer, and the full terms must be one click away.
• Stake limits: £5 per slot spin for players aged 25 and over, £2 for 18 to 24-year-olds.
• No credit cards: gambling on credit has been banned in Great Britain since 14 April 2020.
• Limits first: since 31 October 2025, you are asked to set a financial limit before your first deposit.

Our UK CMA bonus principles page explains where the deposit-withdrawal right comes from.

Is a 300% deposit bonus a good idea?

Only if the deposit is one you were going to make anyway and the terms are clear and within UK limits. Even then, the bonus extends play rather than improving your chances; the house edge applies to every stake, bonus or cash. Our bonus myths guide tackles the most common misunderstandings.

Where to find a real alternative to a 300% deposit bonus

For a percentage match, 10bet has the highest rate among our partners: 18+, new UK customers, choose the casino welcome bonus at sign-up and make your first deposit within 7 days for 100% up to £25. Wager the bonus 10x on slots within 3 days; maximum bonus winnings £1,000; Skrill and Neteller excluded. See the 10bet casino bonus page.

Casumo offers 50% up to £100 on a first deposit of at least £20 (18+, new customers, opt-in required), wagered 10x within 7 days with a £5 maximum bet and game, play and payment restrictions. Our Casumo casino bonus page has the full terms.

PlayOJO gives 80 spins on Big Bass Bonanza, 10p each, with a first deposit of £10 or more and no wagering on winnings (18+, new UK customers, excluding Northern Ireland). Compare everything on our casino bonuses hub.

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