Best Slots Bonuses in the UK for December 2023

We rate and review every online slots bonus we can find, so you can get the best slots bonus in the UK. Find out how to claim a slots sign up bonus and use our wagering calculator to compare slot welcome offers. 

Check out our list below of the best UK casinos with a slots deposit bonus: 

Guide to Finding the Best Slot Bonuses in 2023

Top UK Casino Sites with Slot Bonuses

Best Overall Slot Bonus: Crystal Slots

• Features: spin the Mega Reel to claim up to 500 free spins on the slot game Sweet Bonanza when you sign up and deposit £10.
• Wagering requirements: x65
• Need to know: when you sign up at Crystal Slots and deposit at least £10, you get to spin the Mega Reel with potential prizes including Amazon vouchers and 500 free spins on Sweet Bonanza. Then, after every deposit of £20 or more, you get another spin of the Mega Reel.
• Our view: a bunch of 500 free spins is a great way to get into the swing of things and get to know the casino better. And while the wagering requirements are quite high, it's cool that you could spin the Mega Reel after every £20 deposit.

Crystal Slots Bonus Deposit £10, Get up to 500 Bonus Spins on Sweet Bonanza

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#ad. 18+. Gamble Responsibly. Begambleaware.org. New Customers Only. T&Cs Apply. £10 min fund, Extra spins won via mega reel, 65x bonus wagering requirements, max bonus conversion to real funds equal to lifetime deposits (up to £250).

Best Free Spins Slot Bonus: NetBet

• Features: a 500 free spins slots sign up bonus when you use the code NBWELCOME500 and deposit £10. 
• Wagering requirements: any winnings with the free spins are converted into bonus money and this must be wagered 40 times before you can withdraw any cash.
• Need to know: you get 50 free spins as soon as you make your first qualifying deposit and then you get the remaining 450 free spins in batches of up to 75 spins within six days. Skrill, Neteller and prepaid card payment options are not included in this slots welcome bonus in the UK. 
• Our view: this is a healthy chunk of free spins to start enjoying slots online, and we appreciate the relatively low first deposit amount needed. 

NetBet Bonus Up To 500 Bonus Spins

Promo Code: NBWELCOME500

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#ad. 18+. Gamble Responsibly. Begambleaware.org. New Customers Only. T&Cs Apply. £10+ deposit, no e-wallets/prepaid cards, up to 500 Bonus Spins, 40x wagering on Extra Spins winnings.

Best Cashback Slot Bonus: No Bonus Casino

• Features: 10% cashback on your deposits when you lose all the money you deposited in a single day, forever.
• Wagering requirements: no wagering necessary.
• Need to know: the cashback bonus is available for 10 days after you made the associated deposit. Your balance must be below £10 to activate a cashback withdrawal.
• Our view: we like No Bonus Casino's cashback deal, because it softens the blow of losing bets. What's more, the fact you don't need to wager the bonus makes it very straightforward. We also like how this slot bonus is so different to 99% of others out there.

No Bonus Bonus Always 10% Casino Cashback

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#ad. 18+. Gamble Responsibly. Begambleaware.org. New Customers Only. T&Cs Apply. 10% Cash back without wagering the day after if the player loses all the money in the account. Min deposit £10. Gameplay is monitored.

Best Weekly Slot Bonuses: LeoVegas

• Features: 30 10p free spins on Big Bass Bonanza every Thursday and 10 20p free spins on Rich Wilde and the Book of Dead every Monday.
• Wagering requirements: 4 x wagering on casino games for the Thursday free spins and 3 x wagering on casino games for the Monday free spins. 
• Need to know: to get the Thursday free spins on Big Bass Bonanza, log in and get your offer card between 09:00 and 23:59, before making your deposit of at least £25. For the weekly free spins on Book of Dead, log in between Monday at 09:00 and Wednesday at 23:59, get your offer card, and deposit at least £25. You can also get slots deposit bonuses on new and promoted games like 25 free spins worth up to €1 each on The Bounty Hunter Unchained.
• Our view: LeoVegas has great slots bonuses, including these two weekly offers, and even if these deals are eventually removed, we can imagine them being replaced by other cool bonuses. Book of Dead is one of the most common casino video slots included in slots deposit bonuses, however, giving players free spins every week is pretty rare.

Leo Vegas Bonus Welcome Package up to £100 + 50 Bonus Spins

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#ad. 18+. Gamble Responsibly. Begambleaware.org. New Customers Only. T&Cs Apply. Opt in & deposit £10, £25 or £50 within 7 days & further 7 days to wager cash stakes 35x to unlock reward (£50 on 2 deposits). 3 day exp. Wagering/game contributions vary. 25 wager-extra spins x10p to be added to Big Bass Splash with each qualifying deposit, 3 day expiry.

Best Slots Bonuses in the UK: Honourable Mentions

As well as our star slots bonus sites above, there are hundreds of other great slot welcome offers and deposit bonuses online. Here's a few that didn't make the first draft:

Party Casino

At Party Casino, you can claim 100% welcome bonuses on your first three deposits up to a combined €500, plus 20 free spins on the slot Melon Madness Deluxe. On your first deposit, you get 100% back up to €200 plus the 20 bonus spins, on your second you get a 100% match up to €150, and on your third deposit you get 100% up to €150.

• Need to know: this offer expires at the end of 2023.

MagicRed Casino

MagicRed offers an enticing slots welcome bonus including 100 free spins on the game Big Bass Bonanza, when you follow the 'Visit Site' link on this page and sign up. This is way more than the current 20 free spins welcome offer given to players who don't sign up via Casinos.com.

• Need to know: you only need to deposit €10 to get your 100 free spins, plus there's no wagering requirement on any winnings you collect, you just need to use all your spins before you can withdraw.

Types of Slot Bonuses in the UK 

Online casinos are ever-changing and bonuses evolve too. Any two offers are rarely the same, but plenty have a similar theme.

Below, we highlight a range of bonuses that you can access at several online casinos.

UK Slots Sign Up Bonus

These bonuses welcome new players to the casino. The welcome bonus is the most common type of bonus that you can get as it’s part of a casino’s strategy to get you to sign up.

Free Spins Bonuses

Free spins are a nice taste of the casino’s slots section, allowing you to get to know the casino and perhaps win cash too. You can get these offers on their own or with another offer, like a matched deposit bonus.

The number of casino free spins you get will vary but the winnings will usually need to be wagered before you can withdraw any real money. This means betting the value of the bonus one or more times. These bonuses could also be called bonus spins, extra spins, and super spins.

The following free spins offers are particularly attractive for slots fans: 

CASINO Free Spins Bonus Visit Site

Free Spins 110

Bonus Deposit £10, Get £40 in Bingo Bonuses + 200 Bonus Spins

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#ad. 18+. Gamble Responsibly. Begambleaware.org. New Customers Only. T&Cs Apply. Deposit £10, stake £10 on Bingo, get £30 bonus (x4 Wagering) & £10 Club voucher, &/or stake £10 on slots, get 200 x 10p Fishin’ Frenzy The Big Catch Jackpot King (x20 wagering) & £5 Club slots voucher. Use winnings in cash balance/further deposit to claim both. £5 minimum withdrawal.

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Free Spins 100

Bonus 100% Welcome Bonus up to £50 + 100 Bonus Spins

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#ad. 18+. Gamble Responsibly. Begambleaware.org. New Customers Only. T&Cs Apply. Min £10 deposit & wager. Extra spins on Book of Dead (50 spins on day 1, 25 on day 2, 25 on day 3) 1p coin size. 40x wagering applies. Max cash out £250. Bonus expiry 30 days. Bonus spins expiry 2 days. Game restrictions apply.

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Free Spins 66

Bonus Welcome Bonus up to £66 + 66 Bonus Spins

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#ad. 18+. Gamble Responsibly. Begambleaware.org. New Customers Only. T&Cs Apply. Min deposit £20. Max bonus 100% up to £66 on 1st deposit. 66 spins on Big Bass Bonanza on 2nd deposit. 35x wagering applies, within 21 days. Max wins from spins £100. Spins expire after 24 hours.

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Slots Deposit Bonus

The deposit bonus, or a matched deposit bonus, is very common. This is where the casino site will match the amount that you deposit up to a certain amount, e.g. you get a 100% bonus up to £100.

The value of offers like this vary depending on if you’re a new customer or a returning one. The bigger offers are usually reserved for attracting newbies, however, existing players can earn reload bonuses.

No Deposit Bonus

These are as rare as hens’ teeth these days, but if you’re lucky, you can still grab the odd no deposit bonus for slots. As the name would suggest, this is a bonus that the casino will give you for simply registering an account, with no deposit needed to trigger the bonus.

A bonus which requires no deposit could be free spins, or on a sports betting site, a free bet. Then, you’ll have to wager whatever you win with the bonus. 888casino has a free spins offer where you get 10 spins on slot game Holy Mackerel Extreme Fishing every month of 2023 for no deposit and no wagering. As 888 say, 'You keep what you catch'.

New Slot Promo Offers

Some casinos promote special offers when new slot games are released. It gives players the chance to play real money slots for free.

The offers vary, but they typically include extra spins, slots tournaments with extra prizes based on your wins, gadgets, holidays, and cars.

Reload Bonuses

These offers are for existing players once they have made their initial deposit and usually claimed the welcome offer that goes along with this. Casinos will offer a bonus on a player's 2nd, 3rd, 4th and even up to 5th deposit at that casino.

Cashback

A cashback offer is where the casino site refunds a percentage of your losing bets or deposit from a certain day, weekend, week or month. You might need to hunt for these but they can be found, especially at newer casinos that might work harder to keep you.

Loyalty/VIP Bonuses

Many online casino sites have loyalty programmes with lucrative prizes up for grabs like holidays and cars.

A good loyalty programme will allow you to earn loyalty points whenever you bet. The more games you play, the more points you earn.

With loyalty points, you can progress to the next member level, which can give you reduced wagering contributions on bonuses, a personal account manager, and more cashback every week.

Mobile Slot Bonuses

The success and accessibility of mobile casinos in the UK and the similarity between mobile apps and desktop casinos means that mobile-only offers are now rare.

That being said, it’s worth noting most casinos allow you to clear a bonus by betting on mobile via your browser or their app, on Android or iOS. The only issue is that not all games on desktop are also available on mobile just yet.

Many casino sites have produced casino apps where you can play for real money, so they are worth downloading if you want to play away from home.

Deposit Bonus Slots

Some slot games like Rich Wilde and the Book of Dead and Big Bass Bonanza feature in lots of slots deposit bonuses. There's no single reason for this but these are factors:

• These slots are famous and their names attract new bettors
• These slots usually have an average RTP and some are highly volatile, which means on average, players won't win a fortune from the bonus, which protects the casino from huge losses. Progressive jackpot slots are usually excluded from slots bonuses for this reason.

Popular Deposit Bonus Slots

These are some of the slots we usually see in slot welcome offers and existing players rewards:

• Rich Wilde and the Book of Dead
• Big Bass Bonanza
• Starburst
• Fishin' Frenzy
• Big Irish Bucks
• Eye of Horus

All these slots have an RTP around 96% or lower, which means for every £100 bet, the average player will get £96 back. Of course, you can win much more than 96% or lose more than 4%. Your maximum win potential also depends on any bonus limits. It's important to remember free spins and other deposit bonuses are simply that though—bonuses—so it's best to treat them as a nice added extra.

With thousands of slot games to choose from, it can be difficult to know where to start. To help, we've put together the following list of the most popular slot games in the UK right now. These games are frequently eligible for bonuses, but always read the small print to be sure.

The 10 Most Popular Online Slots

Software Provider

RTP 96.09%

Volatility Low

Maximum win £50,000

Starburst Review and Demo

Software Provider

RTP 96.21%

Volatility High

Maximum win £500

Book of Dead Review and Demo

Software Provider

RTP 96.48%

Volatility Medium

Maximum win £2,110,000

Sweet Bonanza Review and Demo

Software Provider

RTP 95.97%

Volatility Medium

Maximum win £125,000

Gonzo’s Quest Review and Demo

Software Provider

RTP 96.71%

Volatility High

Maximum win £525,000

Big Bass Bonanza Review and Demo

Software Provider

RTP 96.58%

Volatility High

Maximum win £500,000

Legacy of Dead Review and Demo

Software Provider

RTP 96.5%

Volatility High

Maximum win £500,000

Gates of Olympus Review and Demo

Software Provider

RTP 96.31%

Volatility Medium

Maximum win £50,000

Eye of Horus Review and Demo

Software Provider

RTP 96.15%

Volatility Medium

Maximum win £80,000

Fire Joker Review and Demo

Software Provider

RTP 95.98%

Volatility High

Maximum win £240,000

Bonanza Review and Demo

How We Review the Best Slots Bonuses in the UK

Here at Casinos.com we do things a little differently. In fact, one of the reasons that we launched our site is to change the way casinos are reviewed. We don’t want to throw up a generic review and instead, we want to go deeper than other casino review sites.

Our Team of Experts

To do this, we’ve created a dedicated team for each aspect of online casino. This team is set up to find every great online slots bonus, and explain how each works and compares to the rest.

Our team includes professional casino players, game developers and casino writers. The team can cover reviews in greater detail than a one-man-band.

With each review, there’s a basic guideline our team follows, however, it’s not set in stone. And new slot sites pop up all the time, so we try to test all the best new online casinos when they hit the market.

Assessing Bonuses

The first port of call is the bonus and the amount of money on offer. ‘The bigger the better’ is a common misconception as wagering requirements also play a part.

Working through wagering can be challenging so we make sure all the terms and conditions set out by the casino are explained clearly.

Wagering contributions include things like the amount needed to clear the bonus for withdrawal, the time limit on the bonus, games that count, and the maximum bet value allowed with bonus money.

Evaluating What Each Casino Has to Offer

Once the bonus is reviewed, we move onto the wider casino and the number and quality of slot games. This includes the number of mobile slots online that are accessible, since many of you love playing slots on-the-go.

There should be hundreds of slots to choose from at the top sites, and we play-test as many as we can. It’s worth noting that lots of casinos use the same game providers and have many of the same slots, so we give extra points to sites with an original range of great slots. We also love it when a casino offers progressive jackpot slots and a healthy selection of Megaways slots.

Banking and customer support options are key to our reviewers too, as these can make or break your experience. The website might have the best games and bonuses in the world, but if you can’t get money in and out, it’s pointless.

We test bonuses and casinos every day, so check this page later in case we find even better slot bonuses.

Terms and Conditions: What are Wagering Requirements for Slots Bonuses?

The main concept behind wagering requirements is to make sure players don’t simply take the bonus money and run.

A typical offer would be based on 30x your bonus, meaning a £100 bonus would need £3,000 worth of wagers to clear that bonus (30 x £100). 

If you can win and bet £3,000 using the initial £100 bonus money, then you’ll be able to withdraw anything else as cash. The bonus money doesn’t become real money until you reach this point.

Exclusions

Bear in mind that some games will be excluded from wagering — usually, live casino games like blackjack aren’t included or they only count 10% to wagering. On the other hand, casino slots usually count 100% to wagering, although some slots are excluded. 

What’s more, some payment methods can't be used to deposit and claim bonuses, and you generally have to withdraw funds with the same payment method you used to deposit with. You should also remember that most online slots bonus funds expire after a certain number of days.

Is There a Limit on How Much You Can Deposit at a Slot Site?

Yes, while many casino websites offer you the best casino payment methods, you should know each has its own deposit and withdrawal limits, and withdrawal times.

Generally, debit cards and bank transfers offer highest deposit limits, with e-wallets and prepaid cards being lower.

Do All Slots Bonuses Require a Promo Code?

Very few bonuses come with promo codes these days but some still do. Just remember to keep an eye out for a bonus code, so you don’t miss out.

You need to enter the bonus code before making your first deposit or at the time of doing so. You won’t be able to go back and add one if you forget.

Wagering Calculator

If you’re still confused about wagering requirements, you can try our wagering calculator (which opens in a new window when you click the image below)! This makes it easy to understand how much money you need to bet through before you can withdraw your bonus. Just type in your deposit amount, the bonus percentage on offer, e.g. 200%, the wagering requirement, and how much the game, e.g. slots or blackjack, contributes to the bonus, and you'll see how much you need to bet using your bonus money.

A Slot Bonus Tip

Now you know more about the best slots bonuses in the UK, why not try one of the slot welcome offers featured at the top of this page?