Why RTP Numbers Look Different Outside the UKGC System

I once ran an informal test – the same slot title, same provider, loaded at a UKGC-licensed operator and at an offshore site, both with their RTP published in the game rules. The UKGC version showed 94.5%. The offshore version showed 96.5%. Two percentage points, same game, same graphics, same bonus round. For a casual player, that gap looks like the offshore site is simply more generous. For someone who understands how the industry works, that gap tells a story about taxation, margin pressure, and the economics of regulated versus unregulated markets.

RTP – return to player – is the percentage of total wagered money a game is expected to pay back over its lifetime. A 96% RTP means the game retains 4% as the house edge. The figure is calculated across millions of spins, not hundreds, which is the first thing most players get wrong. Your individual session will almost never reflect the published RTP. But the gap between UKGC and offshore RTPs is consistent enough across games and providers that it deserves a proper explanation.

95% vs 96-97% – What Drives the RTP Gap

The short answer is tax. The longer answer involves everything tax touches, which in this industry is everything.

From April 2026, UKGC-licensed operators pay a 40% Remote Gaming Duty on their gross gaming yield. Before that, the rate was 21% – already substantial. GGY is calculated as stakes minus prizes, so when a player wagers 100 pounds and the game returns 95 pounds, the GGY is 5 pounds, and the operator owes 2 pounds of that in tax at the new rate. The tighter the RTP, the higher the GGY per pound wagered, and the more tax revenue per spin. But the operator’s absolute margin also grows with GGY – until the tax takes its share.

Here’s where the economics get interesting. An operator running a 96% RTP game generates 4 pounds of GGY per 100 wagered. At 40% tax, that’s 1.60 in duty, leaving 2.40 before operating costs. Switch to a 94% RTP version of the same game: 6 pounds of GGY, 2.40 in tax, leaving 3.60 before costs. The lower-RTP version produces 50% more pre-cost margin. When your tax bill nearly doubles overnight – the government’s own projections expect the increase to generate 810 million pounds in 2026-27, rising to 1.16 billion by 2030-31 – every operator recalculates which RTP setting keeps them profitable. The result is predictable: UKGC sites trend toward lower-RTP game configurations.

Offshore operators face no equivalent levy. A Curaçao-licensed casino pays an annual licence fee of roughly 47,450 euros and whatever local corporate taxes apply, but nothing resembling a 40% cut of every pound of GGY. They can afford to run the 96% or 97% variant without destroying their margins. An anonymous industry source put it bluntly: the entire business model has changed for onshore operators, and the RTP settings are one of the most visible consequences.

How to Verify RTP Claims at a Non-GamStop Casino

The number on the tin means nothing if you can’t verify it. I’ve seen offshore casinos claim 98% RTP on their homepage with no documentation to back it up. Verification requires checking at two levels – the game itself and the operator.

At the game level, legitimate providers publish RTP figures in the game rules or help menu. Open the slot, find the info or help section, and look for the RTP statement. If the figure matches what the casino advertises, and the game is from a recognised provider – Pragmatic Play, NetEnt, Play’n GO, Microgaming – the published number is almost certainly accurate. These providers submit to third-party audits from testing houses like eCOGRA, iTech Labs, or GLI, and they don’t risk their reputation by allowing operators to alter the RTP without authorisation.

At the operator level, the question is whether the casino is actually running the version it claims to run. Some providers allow operators to choose between multiple RTP settings, and the operator may not always display the correct one. The safest check is to cross-reference the game’s RTP with the provider’s official game sheet, which most major providers publish on their corporate websites. If the casino’s stated RTP exceeds the highest setting the provider offers for that title, something is wrong.

Be especially cautious with providers you don’t recognise. Smaller studios supplying exclusively to offshore markets may not undergo the same level of independent auditing. A game labelled “provably fair” by an unknown provider isn’t the same as a game audited by eCOGRA. The terminology sounds similar, but the verification depth is completely different.

The 40% RGD and Its Likely Pressure on UKGC Operator Payouts

The RTP gap between UKGC and offshore is not static. It is going to widen. The government’s Office for Budget Responsibility has projected that operators will pass up to 90% of the increased tax burden through to consumers via worse odds and reduced payouts. That’s not speculation – it’s the government’s own modelling of how the market will respond to the duty increase.

For slots specifically, “worse payouts” translates directly into lower RTP settings. If UKGC operators were already trending toward 94-95% configurations under a 21% duty, a 40% duty accelerates that trend. Offshore operators, meanwhile, have no reason to change. The gap that currently sits at roughly two percentage points could easily stretch to three or four as the new tax regime beds in. For a player comparing the same game across two sites, that widening gap makes the offshore version look increasingly attractive – which is precisely the dynamic that H2 Gambling Capital modelled when it projected offshore iGaming activity could grow by approximately 110% following the Remote Gaming Duty increase.