A 400 casino bonus is one of the most generous offers you’ll find at a gambling site. It gives you the chance to get a massive boost to your gambling funds, so long as you meet the deposit requirements on offer. 

Very few casinos offer a 400 casino bonus and those that do regularly update their offers, so you often need to act quickly if you want to get the reward. 

Our guide covers all the things you need to know about a 400 casino bonus, such as: 

• How we review sites that offer this bonus 

• Safety and security of UK online casinos 

• Tips on playing the best casino games 

• The key bonuses offered by gambling sites 

• Wagering requirements for casino bonuses 

All you need to do is read our guide, decide if a 400 casino bonus is right for you and then sign up to the sites that offer this reward. 

How we review the top sites with a 400 casino bonus 

OnlineCasinos.co.uk has a reviews process that we’re very proud of. 

We look at all the important details of the online casinos we review, assessing them as players, for players. These are some of the key questions our expert reviewers ask themselves when carrying out their assessments: 

Casino games available 

• Do the casino sites have the quantity and quality of games you demand? 

• Are the games available to play on all of your devices (mobile and PC)?

• Do the sites provide a wide range of betting limits to satisfy all players? 

Sports betting options 

• Can you wager on all of the sports that you’d expect to be able to? 

• Are there good, competitive odds on offer from the online casinos?

• Does the online casino feature a diverse range of betting options?  

Bonus code offerings 

• Can you get a minimum deposit bonus from the online casino? 

• Are there free spins on offer that can be used on top slot games?

• Does the site offer a welcome bonus package to its new players? 

We do this to make sure you can feel safe and secure at your favourite casino sites. This means all you need to worry about is picking the sites you like the most and selecting your favourite games to play at them. 

Safety and security at casino sites based in the UK 

Safety and security is one of the most important things to the expert reviews team at OnlineCasinos.co.uk. 

We need to be 100% certain that every online casino operator we cover is safe and secure because you provide them with very sensitive information, from photo ID to your bank account details. 

That’s why our experts check every online casino they review to see if it has a UK gambling license number, so they know it’s been approved by the UK government — we’ve included the license numbers of every site featured in this guide at the top of the page, so you can see for yourself that it’s trustworthy. 

But our checks go deeper than this. We also look to see if a site is registered with any other gambling regulators and if it makes it simple for its players to get in touch with responsible gambling organisations

We do this by looking for the following icons on the website: 

Gambling regulators 

• Government of Gibraltar

• Malta Gaming Authority 

• Spelinspektionen

Responsible gambling organisations

• GameCare

• GAMSTOP

Only once we’ve satisfied these requirements do we carry out a review. So you can be certain that all the casino sites we review are safe and secure. 

How to play the top games at online casinos with a 400 bonus

Games are the reason you visit an online casino. They’re where you can test yourself against a computer or live dealer, have fun applying your gambling strategies and (hopefully) win some money. 

We believe it’s important that players of all levels of experience can have fun playing casino games. Below, we’ve included tips on how to play the top games: 

Slots 

• Pick the slot variant you’re interested in — such as progressive slots and mega spin.

• Look for the games RTP (return to player) — it highlights your chances of winning. 

• Be mindful of betting limits — play games with min and max limits you’re happy with. 

Roulette 

• Decide if you want to play European or American — there’s a subtle difference. 

• Study up on the betting strategies — there’s a range of approaches you can use 

• Think about live or video games — live dealer roulette games have higher bet limits 

Blackjack 

• Understand the rules of blackjack gambling — so you can enjoy the games you play 

• Learn the basic blackjack strategy — it will help when you make your wagers 

• Try some free blackjack games — to give you some space to practice your approach 

Poker  

• Begin by playing Texas hold 'em — it’s the easiest and most popular poker variant 

• Review the poker hand rankings — so you know if you’re in a good or a bad position 

• Get tips from a poker pro — Doug Polk is one of the many pros with some top tips 

Casino bonuses 

Whether it’s a new or established casino, a site with a 400 casino bonus or one with a great loyalty package, bonuses are a vital part of picking the right gambling site. 

Casino bonuses give you an opportunity to earn some cash or credit to use on your favourite games. This means you can have longer games and could increase your chances of winning some money from your gambling sessions. 

Welcome bonus 

Welcome bonuses are one of the most popular casino bonus offers. Almost every UK site has a welcome bonus package for its new players, as it’s one of the key ways casinos attract new players. Welcome bonuses include cash offers and free spins, with many of the leading sites offering a combination of the two. 

Minimum deposit bonus 

Minimum deposit bonuses are a standard at many of the best sites in the UK and are a feature of 400 casino bonus offers. You need to make a qualifying deposit to be eligible for these offers, such as making a minimum credit of £10 to your account. 

Deposit match bonus 

Deposit match bonus offers are exactly what they sound like — you make an initial deposit amount and the casino will match it. It’s not unusual for a 400 deposit bonus to come with these terms and conditions, as many sites base the provision of a large reward on the amount of money players are willing to contribute to their accounts. The deposit amount varies from bonus to bonus and it may be that you need to make multiple minimum credits to get the full reward on offer. 

Free spins 

Free spins are possibly the most popular offer used by online casinos, which makes sense because slots are generally the best-represented game at casino sites. You can use a bonus code (or bonus codes if you’re signing up to multiple casinos) to earn free spins on leading slots titles. Though, you should always check the T&Cs of the bonus you’re thinking of signing up to because it may be that the free spins are only available for certain games. 

What is a 400 deposit bonus?

A 400 casino bonus is when a casino site matches your deposit (usually your initial deposit) by 400% — so, if you make a deposit of £100 then you could earn a reward of £400, meaning you’d have £500 in your gambling account. 

400 casino bonuses are among the most generous you’ll find at a gambling site and this means they often come with tough terms and conditions, such as high wagering requirements. 

Ultimately, a 400 casino bonus is another way for you to increase the amount of money you have to wager with at your favourite casino sites. 

How can I claim a 400% first deposit bonus?

Online casinos make it as simple as possible for you to claim a 400% first deposit casino bonus. This is because they want it to be easy for you to boost your account balance and have more money to play with. 

While each site has a slightly different process for activating its bonus codes, you can generally claim your 400% casino bonus by following a process like the one below: 

• Locate an online casino with a 400% first deposit bonus 

• Click on the bonus offer and make sure you get to the sign-up page 

• Make the deposit(s) required to get the full bonus amount

Of course, if the reward is for new players then you’ll also need to create an account with the online casino with the bonus you want to sign up for. 

If you’re signing up as a new player then you’ll also need to prove you’re old enough to gamble by supplying ID. You’ll need to provide the following documents: 

• Photo ID: such as a passport or driving license. 

• Proof of address: like a utility bill 

One last thing to keep in mind is that you might need to use a bonus code (or bonus codes if you’re signing up for rewards at numerous casinos) to get your reward. The site will make it clear if you need to provide a bonus code and highlight where you need to enter it. 

Do many casino sites offer a 400% bonus?

Because 400% casino bonus offers are so generous, it’s rare for a site to offer this reward. For the simple reason, they have to give so much cash to players — despite the fact the site will expect to make much of this back in wagers made on its games. 

This means that you’ll often find a 400% casino bonus offered by new sites, rather than their established rivals. 

This is because new sites have to work harder to attract new players, as they don’t have decades (in some cases) of experience in the industry and corresponding brand strength. 

Pros & cons of a 400% casino bonus 

Like all rewards offered by gambling sites, there are both pros and cons to signing up for a 400% casino bonus. Below, we highlight the key pros and cons of this offer. 

Pros

• It gives you a massive boost to your casino account 

• You can play more games because you have more credit 

• The bonus often comes with a free spins offer 

Cons 

• You may have to meet stiff wagering requirements 

• You may have to invest a lot of your own cash to get the full offer 

• It puts a real focus on your ability to gamble responsibly 

Terms and Conditions

Every single UK casino bonus comes with terms and conditions that must be published in full by the gambling site offering it. This is a legal requirement imposed by the Gambling Commission, to ensure UK players are fully aware of what they need to do to get the bonus. 

Each offer will have unique T&Cs but these are some of the things you can expect to find: 

• Amount of money you need to invest to get the bonus 

• Number of deposits you need to make to receive the full amount

• Timescale you need to make your deposits within 

• Wagering requirements necessary to receive the benefits of the reward 

You can find the terms and conditions of a casino bonus in the promotions section of an online casino. We recommend you read them in full before signing up for the offer, so you’re certain it’s right for you. 

Wagering Requirements

Wagering requirements are one of the most important parts of rewards offered by online casinos, including a 400 casino bonus. 

Wagering requirements are the amount of your own cash you need to invest to be able to withdraw the winnings you make from a bonus. They’re represented as a number followed by an x, which means this is the number of times you need to wager the amount of the bonus to get the benefits of the offer. 

Using the example of a £100 welcome bonus, this is how wagering requirements work: 

• 10x: you need to wager £1,000 to withdraw the winnings you make from the bonus. 

• 25x: you need to wager £25,000 to withdraw the winnings you make from the bonus. 

• 50x: you need to wager £50,000 to withdraw the winnings you make from the bonus. 

You should always check the wagering requirements of a casino bonus before you sign up for it. If you don’t then you might find you need to wager a lot of your own cash before you can withdraw your winnings. 

Best casino for a 400% bonuses

There are only a select few casinos that are generous enough to offer a 400% casino bonus. But that doesn’t mean there aren’t great sites that have a 400% reward for their players. Below, we’ve highlighted the best casino with a 400% bonus. 

We’ve picked just our top casino because sites regularly update their bonuses and this means it’s rare for one to keep a 400% offer indefinitely. 

However, if you check in regularly at sites such as La Fiesta Casino and Lucky Red Casino then you might find they also have a 400% bonus. 

Unibet Casino 

Credit: Unibet 

OnlineCasinos.co.uk 400 casino bonus rating: ⭐⭐⭐⭐⭐

Unibet is one of the best sports betting sites and one of the top casinos with a 400 casino bonus. It has a superb range of sports for you to bet on, along with a great selection of video and live casino games. 

Three things you’ll like most about Unibet Casino 

• Enormous range of sports betting options 

• Great selection of casino tournaments 

• Excellent community for gambling fans 

Visit Unibet Casino now to find out more about one of the UK’s best online casinos. 

Some other great casinos you can bet at 

Unibet is our top pick for players looking for a site with a 400 casino bonus. But Unibet isn’t the only great casino you can bet at. Below, we’ve listed some of the other leading gambling sites for UK players. 

Casimba Casino 

Credit: Casimba 

OnlineCasinos.co.uk 400 casino bonus rating: ⭐⭐⭐⭐⭐

Casimba Casino is one of the top gambling sites for UK players. It has an enormous amount of games, features some of the best casino software providers and often has a great bonus package for new and returning players. 

Three things you’ll like most about Casimba Casino 

• Really user-friendly website 

• Great for mobile gambling 

• Huge amount of slot games 

Read our Casimba Casino review to learn more about this outstanding gambling site. 

Genesis Casino 

Credit: Genesis 

OnlineCasinos.co.uk 400 casino bonus rating: ⭐⭐⭐⭐⭐

Genesis Casino is perfect for UK players. It has a great selection of video and live casino games, often has a generous welcome package and a range of fast withdrawal casino options for UK gamblers. 

Three things you’ll like most about Genesis Casino 

• Outstanding payouts for its blackjack games 

• Superb range of live casino table games 

• Known to have an impressive welcome package 

Check out our Genesis Casino review to discover more about this ace UK casino site. 

Mansion Casino 

Credit: Mansion

OnlineCasinos.co.uk 400 casino bonus rating: ⭐⭐⭐⭐⭐

Loads of real money games? Check. Tonnes of live table games? Yep. Huge amount of slot games? You bet. Mansion Casino is ideal for players who demand variety to their casino gaming experience — and it’s bonuses are often among the most generous you’ll find. 

Three things you’ll like most about Mansion Casino

• Min and max betting limits are perfect for new players 

• Exceptional offering for people who like to bet on their phone

• Features lots of games you won’t find at most casino sites 

Give our Mansion Casino review a read to get our full thoughts about this top-rated casino.