Varying RTP Rates at UK Slot Sites


With various RTP rates available on most online slot games, we go deep into the actual RTP rates offered by UK slot sites. Review sites like will tend to push the highest RTP of any game but we look into what players are actually getting when playing slots online. Firstly, a bit of background.

About RTP Rates in Slots

Return to Player rates (or RTP) in slots is the theoretical payout rate available on a particular slot game. If an online slot has an RTP of 96%, you will theoretically win £96 back when wagering/betting £100 on average. This gives the slot site or casino a 4% margin or house edge.

Lower the RTP to 94% and the site makes a 6% margin (£6). If you apply this to tens of millions of pounds of wagering, the difference will be substantial. The higher the RTP rate, the less the slot site makes on average per spin. However, the RTP rate is the guaranteed return across millions or billions of spins. You may be the lucky player who wins lots but other players will lose in order to make up that guaranteed return rate.

Regulatory Pressures

In Germany for example, the new State Treaty on Gambling (GlüNeuRStv) implemented a 5.3% turnover tax on online slots which has led to a reduction in RTP rates by operators. As a result, slot providers now offer an RTP rate of around 92% for their games.

On the 28th of May 2021, the Malta Gaming Authority announced that they lowered the existing minimum RTP percentage from 92% to 85%. This allows online operators and suppliers to offer their games in jurisdictions with high taxes, such as Germany.

Slot providers these days tend to produce different RTP options for their customers (i.e. slot sites/casinos). If you take Play ‘n GO for example, there are 5 RTP rates to choose from for all their slot games. This is to accommodate the needs of various slot sites they work with due to legislation implemented by respective governments.

UK Slots Market

In the UK, the competition amongst the top slot sites is greater than ever. With many household brands now advertising online and on TV (as well as radio and other verticals), being the place to play the best online slots is the operators’ aim.

Whilst competition is good in general, it is harder to attract new players as well as come away with a black balance sheet. An easy way to increase revenues is to lower RTP rates on online slots. With no minimum RTP rate on a gaming machine in the UK according to the UK Gambling Commission, you will find different RTP rates on the same slot games at different casinos or slot sites.

If you take the popular Book of Dead slot by Play ‘n GO, there are 5 RTP rates to choose from. The highest is 96.21% and the lowest is 84.18%. Below is a table showcasing the house edge and different margins when applying the different RTP rates to £1 million in bets:

RTP Rate House Edge Overall Slot Site’s Margin
96.21% 3.79% £37,900
94.25% 5.75% £57,500
91.25% 8.75% £87,500
87.25% 12.75% £127,500
84.18% 15.82% £158,200

If a UK site were to offer the 84.18% RTP rate as opposed to the 96.21% RTP for Book of Dead, the profit margin would be £120,300 more for just £1 million in bets. That’s a 12.03% difference.

Which Slot Sites offer the Highest RTP Rates?

Due to increased costs incurred by legislation and fierce competition, slot sites in the UK have to find ways to balance the books. As a result, we’ve found many sites offering lower RTP rates than the maximum allowed on the vast majority of online slots they offer.

We decided to look at the RTP rates for 15 slot games from a wide range of reputable and licensed slot providers. Some online slots weren’t available at all casinos so we also looked at some newer releases. Furthermore, slot providers may only offer 1 RTP rate on older releases.

It’s also important to note that not all slot sites offered all the slot games we looked at. RTP rates were compared across 13 UK-facing slot sites. These include LeoVegas, MrQ, Unibet, Casumo, Duelz, Casushi, Playzee, Jackpot Casino, PokerStars Casino, PlayOJO, All British Casino, Mr Green and NetBet.

Of the slot games we looked at, the highest RTP rate possible was used at 33.33% of UK slot sites. Here are the results:

Online Slot Provider Best RTP Rate Casinos with Best RTP
Money Train 4 Relax Gaming 96.1% 45.45% (5/11)
Sweet Bonanza Pragmatic Play 96.49% 16.67% (2/12)
The Goonies Hey You Guys Blueprint Gaming 95% 14.29% (1/7)
Book of Dead Play ‘n GO 96.21% 16.67% (2/12)
Starburst NetEnt 96.09% 23.08% (3/13)
Immortal Romance Microgaming 96.86% 66.67% (8/12)
Razor Returns Push Gaming 96.55% 25% (2/8)
Candyfinity Yggdrasil Gaming 96% 57.14% (4/7)
San Quentin Nolimit City 96.03% 40% (4/10)
Odin’s Gamble Thunderkick 96.17% 33.33% (3/9)
RIP City Hacksaw Gaming 96.22% 22.22% (2/9)
Brooklyn Bootleggers Quickspin 96.25% 16.67% (1/6)
10000 BC DoubleMax 4ThePlayer 96% 37.5% (3/8)
The Walking Dead Playtech 95.73% 25% (1/4)
Reapers Print Studios 96.47% 57.14% (4/7)

High RTP Rates for All Big Time Gaming Slots

Reassuringly, slot provider Big Time Gaming only offers 1 RTP rate for their slots. With higher than the 96% average RTP rates across the board, you are guaranteed to be playing the highest RTP rate for the likes of Bonanza Megaways, Lil’ Devil and Danger High Voltage as there only is one available.

Slots with the Top RTP Rates

Many savvy players will always play slots with the best RTP rates. With up to 99% RTP rates available (for Relax Gaming’s Book of 99), anything over 97% is considered very high. Whilst these payout rates are very high, you cannot be guaranteed to find that rate at your preferred slot site.

MrQ Casino: The Shining Star


Of the online slot sites we looked at, there was 1 clear winner: MrQ Casino. When looking at 11 of the 15 slots on our list, MrQ offers the highest RTP rate for 100% of slot games. To showcase the RTP rate they offer, the RTP is clearly displayed when you fire up a slot game (see image above).

Speaking to James Booth (Head of Acquisition at MrQ), he commented:

“At MrQ, our mission is to provide ‘value entertainment’ and that puts the customer experience at the heart of everything we do. We’ve noticed an industry trend among other operators to increase ‘house win’ and boost profit margins. So, we decided to buck that trend in the hope that customers would understand the benefit of playing with the highest possible RTPs and stay loyal to MrQ as a result. So far we have had some amazing feedback from our customers and it seems, this potentially risky, long-term strategy is paying off.”

James also predicts that more transparency will be needed in future:

“We also predict that increased regulation of the industry will demand more transparency from operators to publish RTPs more obviously in the future, and if that does come true, we’re one step ahead of the curve in taking proactive steps to enhance the experience of each and every customer.”

Finally, he commented that MrQ is here for the long term and focused on sustainability:

“Ultimately, MrQ is here for the long term and where other brands will come and go, earning a quick buck in the process, MrQ believes in a sustainable and fruitful future of the UK casino industry.


RTP in slot games is a delicate subject. With increased competition, it’s sure to continue as slot sites aim to make a profit as well as provide an appealing service to their customers. We hope more operators follow in the footsteps of MrQ and are as customer-focused as they are. That said, the likes of Unibet display the RTP rates for their slots even though they don’t always offer the highest RTP possible.

Whilst, as slots players, we want the highest RTP rates and for them to be clearly displayed, what we can hope for is that the RTP % is displayed clearly and prominently when playing a slot game. This way, we can choose whether to accept it or not.

Martin Backhouse
Review by
Last updated: April 02, 2024

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