Casino game testing labs

What casino game testing labs do

In the Commission's words, 'Test Houses play a vital role in ensuring games are fair to consumers'. A test house is a specialist company that examines gambling software and equipment against the regulator's technical standards and writes a report on whether it passes. For online games, the benchmark is the Remote Technical Standards, especially RTS 3 (rules and chances of winning) and RTS 7 (random outcomes).

The Commission's testing strategy (opens in a new tab) says certain licence categories must have games and RNGs tested by an independent test house from its approved list, and that new games and RNGs can only be released once testing is complete and the report has been provided to the Commission. Our companion page on how casino games are tested walks through each stage of that process; this page is about the labs themselves and how to read their work.

The UK's approved casino game testing labs

The Commission's approved test houses page (opens in a new tab) listed the following labs when it was checked in October 2026. Every one is approved for the Remote Technical Standards, which is the approval that matters for online casino games. Several belong to the same groups, which is why GLI and BMM appear more than once.

The list changes over time as labs are added or removed. Treat the table as a snapshot and check the Commission's page for the current position.

Not every lab is approved for everything

The Commission's test houses guidance (opens in a new tab) warns that not all test houses are approved in every area, so licensees must check that a lab is approved for the type of gambling they offer. The list splits approval into three broad areas: the Remote Technical Standards for online games, the categories of land-based gaming machines, and bingo and casino equipment.

For someone playing online, the first column is the one that counts. A lab with only remote approval can sign off an online slot or RNG roulette game, but not a fruit machine in a pub or a roulette wheel in a land-based casino. Our page on land-based casinos covers the rules for physical venues.

Lab names you may see that are not on the UK list

Casino footers and game screens sometimes carry testing badges. A badge tells you a lab looked at something, but not necessarily that the lab is approved by the British regulator. When the Commission's list was checked in October 2026, NMi and iTech Labs did not appear on it, so neither should be described as UKGC-approved on the strength of that list.

That doesn't make a game unsafe on its own. What protects you is the operator's British licence, because the licence is what makes testing by an approved lab compulsory. If a site shows a lab badge but holds no Gambling Commission licence, the badge offers you none of the protection a UK licence does. Our licence-checking guide shows how to confirm an operator on the public register.

A test house's jobs, from first build to annual audit

The testing strategy describes a clear sequence of work for each new game or generator:

1. Receive the game or RNG from the supplier, together with its documentation, rules and pay table.
2. Review the RNG's documents and source code, then run statistical tests on its raw output.
3. Test the game's design and software, and measure its actual RTP through simulation, emulation and manual testing.
4. Write the test report and provide it to the Commission; only then can the game be released.
5. Have the report uploaded to the licensee's games register through the Commission's eServices system.
6. Audit, once a year, any updates the supplier has made through its approved in-house change process.

There is one narrow exception in the strategy. Remote lottery licensees with entries of £250,000 or less a year need not use a Commission-approved lab for their RNG, but must show it was verified as fair and random by an independent, suitably qualified third party. That exception does not cover online casino games.

Why labs simulate millions of rounds to confirm an RTP

When a lab measures a game's RTP by simulation, it is estimating a long-run average from a finite sample. The accuracy of that estimate depends on two things: how many rounds are played and how much each round swings. Casino Math, the standard textbook by Hannum and Cabot, gives the expected range of a game's actual payback after n plays as the theoretical payback plus or minus a volatility index divided by the square root of n, with the index usually set at 1.65 times the per-unit standard deviation for 90% confidence.

An even-money bet on single-zero roulette has a standard deviation of almost exactly 1 unit per bet. Plug that in and you can see why short tests are useless:

Each hundredfold increase in rounds makes the range ten times tighter, because precision improves with the square root of the sample. Slots swing far more per spin than a bet on red, so a lab needs even larger runs to pin down a slot's return to the same precision. If a game's per-spin standard deviation were ten times that of the roulette bet, it would need a hundred times as many simulated spins for the same accuracy. The law of large numbers and volatility pages explain both ideas in more depth.

A lab passes a game, not a good bet

Testing confirms that a game pays exactly what its rules say. It does not judge whether those rules are generous. Some fully tested bets cost many times more than others, and the lab signs them all off because they behave as described. Figures below are standard game maths from the Wizard of Odds house edge list (opens in a new tab) and its game pages, with the average cost of a £10 bet shown in pounds.

The same applies to rule changes. A blackjack game paying 6 to 5 on a blackjack instead of 3 to 2 costs the player an extra 1.39%, as our 3:2 against 6:5 page explains, yet both versions pass testing as long as they pay what their rules state. The baccarat tie bet and sic bo bets pages break down why the pay table, not the lab, decides the cost. For a ranked list, see the worst bets in the casino.

Who pays the labs, and why independence still holds

Game suppliers and operators commission and pay for testing, which raises a fair question about independence. The safeguard is that the Commission, not the supplier, decides which labs may do the work. A lab that wants to stay on the approved list has to test to the Commission's standards, and its reports go to the regulator before a game can launch. Suppliers need their own licences too, which our remote licences page explains.

Many players never see a lab's name, because the work happens with the game provider before a title reaches any casino lobby. Our slot providers section covers the studios themselves.

How to use test-house information as a player

1. Start with the licence, not the badge: confirm the casino holds a Gambling Commission licence.
2. If a footer names a testing lab, compare the name against the Commission's approved list.
3. Open each game's help screen to find its RTP or house edge, which UK rules require before you play.
4. Compare bets inside a game, because the cheapest and dearest options can differ by more than ten times.
5. Set a budget based on the house edge, since testing confirms the edge rather than removing it.

Myths about casino testing labs

If you want to know more about the regulator behind the list, read our guide to the Gambling Commission, or head back to the casino maths hub for related topics.

Playing lab-tested games at UK casinos

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18+. Every casino game has a built-in house edge, so over time you should expect to lose what you stake. Set a budget before you play and stop when it’s gone: safer gambling tools and support. Free, confidential help: National Gambling Helpline 0808 8020 133.