400% deposit bonus

A 400% deposit bonus in plain numbers

The rule is simple: bonus = deposit × 4. A £5 deposit earns £20 of bonus, £10 earns £40 and £25 earns £100, unless the bonus cap stops it sooner. Your total balance is five times what you paid in, but only one-fifth of it is your money.

That last point is the heart of any 400% offer. Most of the balance belongs to the casino until you meet the terms, and the larger the bonus share, the more those terms control what you can do with it. As a form of casino match bonus, it is only for adults aged 18 or over and full terms apply.

Who offers a 400% deposit bonus in the UK?

None of our five partners. Our last check of their offers, on 5 October 2026, found two percentage matches (10bet at 100% up to £25 and Casumo at 50% up to £100) and three free spins deals. Nothing in that list approaches 400%, and we would rather say so than pad the page with offers we can’t stand behind.

At UK-licensed casinos a 400% rate would be exceptional under the current wagering cap. You are more likely to see it in adverts from sites that are not licensed for Great Britain, which brings different risks covered further down. Our UK vs non-UK casino bonus comparison explains the difference in protection.

Percentages and “play with” headlines: a conversion table

Many offers skip the percentage and say “deposit X, play with Y”. To convert, subtract the deposit from the “play with” figure to get the bonus, then divide the bonus by the deposit. Deposit £10, play with £50 means a £40 bonus, which is 400%.

Our pages on deposit £10 play with £50 and deposit £5 play with £25 look at the two 400% versions of that headline in detail, and deposit £20 play with £60 covers the 200% case.

The small-deposit problem with a 400% rate

Very high percentages are almost always attached to small deposits, because a small deposit keeps the casino’s outlay low. That means minimum deposit rules matter. Casumo, for example, sets a £10 minimum for all payment methods and a £20 minimum for its welcome offer; our minimum deposit for a bonus answer covers the rest of the market.

At £5, a 400% bonus gives £20; at £10, £40. Those are small sums in pounds even though the percentage is large. Before your first deposit, UK-licensed casinos must prompt you to set a financial limit (since 31 October 2025), which is the right moment to decide what you are willing to spend before the bonus enters the picture. Our £5 deposit bonus page looks at what low deposits realistically get.

400% deposit bonus wagering at 10x

The UK cap applies to the bonus: SR code 5.1.1 (opens in a new tab) limits wagering to 10 times the bonus funds. On a 400% match, that equals 40 times your deposit. It is the steepest wagering-to-deposit ratio of any common percentage.

The average cost column applies a 4% house edge, typical of a slot with 96% RTP, to the full wagering. Real sessions vary a great deal, and with UK slots limited to one spin every 2.5 seconds at minimum, 800 spins is more than half an hour of continuous play. If the staking needed is more than you would normally do, the offer is not a good fit. Our wagering requirements guide shows how to read any figure.

Why UK-licensed operators keep match rates far below 400%

At 10x wagering, the house edge on the required play recovers only part of a bonus: about 40% of it on a 96% RTP slot. On a £40 bonus that is about £16. Under the heavier wagering common before 2026, the same bonus could be recovered in full, which is how big percentages were affordable for operators.

With that lever gone, a 400% deal would give away far more than most operators are willing to fund, especially with remote gaming duty on operators rising to 40% of gaming profits from 1 April 2026. The Gambling Commission’s consultation response on socially responsible incentives (opens in a new tab) set out the decision to cap wagering rather than ban it, and our UK 10x wagering cap page covers the detail.

How a 400% offer would be credited and cleared

1. You register, pass the age and identity checks and set a financial limit.
2. You opt in, if required, and deposit with a payment method the offer accepts.
3. The casino credits the bonus (deposit × 4, up to the cap) to a separate bonus balance.
4. You play eligible games within the maximum bet; each stake counts towards the wagering at its contribution rate.
5. When the wagering is complete within the expiry, the remaining bonus balance converts to cash, subject to any maximum win.
6. If the balance runs out or the expiry passes first, the bonus and its winnings are removed; any deposit balance left stays yours.

Our guide to how to check wagering progress shows where to see how far through you are.

Maximum win caps and why they bite on large multiples

A large bonus often comes with a ceiling on what bonus play can pay out, known as a max cashout or maximum win. 10bet’s welcome bonus caps bonus winnings at £1,000, for example. Anything above the cap is removed when the bonus converts to cash.

Caps are not unfair in themselves, but they must be shown clearly as a significant term. On a 400% offer with a low cap, a lucky session could produce winnings that are mostly removed. Combined with a maximum bet rule, which Casumo sets at £5 per bet with an active bonus, and the legal slot stake limits of £5 (25+) and £2 (18–24), the outcome of bonus play is tightly bounded. Our casino bonus max win page explains how caps are applied in practice.

400% next to the offers you can actually claim

The 400% example wins on headline size, but it is the only one on this list you can’t claim from a partner. Of the real offers, 10bet gives the most bonus per pound up to £25, and PlayOJO is the simplest to value because winnings are paid in cash. Our PlayOJO vs 10bet comparison weighs those two directly.

Is a 400% deposit bonus worth looking for?

We would say no. The percentage is large, but the pounds involved are small, the wagering relative to your deposit is the highest of any common match rate, and the offers that use it are mostly found where UK protections don’t apply. A bonus never changes the house edge or makes losses less likely over time.

If gambling stops feeling like entertainment, the National Gambling Helpline on 0808 8020 133 is free and open 24 hours a day, and our bonuses and gambling harm guide explains how to step back from offers.

Where to look instead of a 400% deposit bonus

10bet’s match is the strongest percentage among our partners: 18+, new UK customers, select the casino welcome bonus at sign-up and make your first deposit within 7 days for a 100% bonus up to £25. Wager it 10x on slots within 3 days; bonus winnings are capped at £1,000 and Skrill and Neteller deposits are excluded. Read more on the 10bet casino bonus page.

Casumo’s 50% up to £100 needs a first deposit of £20 or more and an opt-in (18+, new customers); wager the bonus 10x within 7 days, £5 maximum bet, game, play and payment restrictions apply. See the Casumo casino bonus page.

PlayOJO avoids wagering entirely: 80 spins on Big Bass Bonanza at 10p each after a first deposit of at least £10, with winnings paid as cash (18+, new UK customers, not Northern Ireland). Every offer is 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.