When you play at an online casino, you are trusting that the games are fair. But how do you actually know they are? The answer lies in third-party auditing, an independent process that verifies whether a casino’s games work exactly as they claim to.
Online casino games are audited by accredited testing laboratories that check Random Number Generators (RNGs), confirm Return to Player (RTP) percentages, and inspect game code for signs of manipulation. The most recognised auditing bodies are eCOGRA, iTech Labs, and GLI (Gaming Laboratories International).
This article explains what that process involves, which organisations carry it out, what they test, and how you can check for yourself whether a casino’s games have been independently verified. If you are not yet familiar with how RNGs work, reading What is RNG in Online Casinos? first is worthwhile, as it makes it easier to understand why auditing them matters.
What Third-Party Auditing Means in Online Casinos
Third-party auditing means an independent organisation, one with no financial relationship with the casino, examines the software and confirms it works as described.
The key word is “independent.” A casino’s own team can run internal checks, but those carry limited value because the casino has a direct interest in the result. An accredited external laboratory has no such interest. Its job is to apply standardised testing methods and report findings objectively, regardless of what they find.
This is not a one-time process. Licensed operators must have their games tested before release and continue to meet compliance requirements on an ongoing basis. Licensing bodies such as the Malta Gaming Authority require regular audits as a condition of holding a licence, and operators that fall short face sanctions including suspension or loss of that licence.
Which Organisations Audit Online Casino Games?
Several internationally accredited organisations carry out these audits. The three most widely recognised are eCOGRA, iTech Labs, and GLI, though others such as BMM Testlabs, Technical Systems Testing (TST), NMi, and QUINEL are also respected within the industry.
| Auditing Body | Full Name | Founded | Areas of Testing | Recognised By |
| eCOGRA | eCommerce Online Gaming Regulation and Assurance | 2003 | RNG fairness, RTP accuracy, player protection | MGA, UKGC, and others |
| iTech Labs | iTech Labs | 1998 | RNG, game mathematics, system integrity | MGA, UKGC, multiple regulators globally |
| GLI | Gaming Laboratories International | 1989 | RNG, RTP, security testing | Over 475 regulators worldwide |
eCOGRA was one of the first bodies created specifically for online gambling oversight. It tests RNG performance, verifies RTP accuracy, and reviews player protection standards.
iTech Labs, based in Australia, issues certificates per game or platform, so each product must pass its own checks individually.
GLI is the most globally recognised of the three, operating since 1989 and accepted by over 475 regulatory bodies worldwide.
A valid certificate from any of these organisations means a casino’s games have been assessed against established industry standards.
What Auditors Actually Test
Understanding what auditors check helps you appreciate what a certificate genuinely guarantees, and where its limits lie.
RNG Testing
This sits at the core of any audit. Auditors run the RNG algorithm through millions of simulated game rounds and examine the results statistically. The goal is to confirm that outcomes follow no predictable pattern and that previous results have no bearing on future ones.
In plain terms: every spin or card deal is genuinely independent, and neither the casino nor any pattern in previous rounds can influence what happens next.
RTP Verification
Return to Player is the percentage of total stakes a game pays back to players over time. A game with a 96% RTP should return £96 for every £100 wagered across a very large number of rounds. Auditors check that a game’s actual payout behaviour matches its published figure.
Without independent testing, an operator could advertise one RTP figure while the game performs differently in practice. This check ensures the number you see is the number that applies.
Source Code Review
Some audits go further and examine the game’s underlying code. This allows auditors to check for any hidden instructions or programming that could allow outcomes to be altered outside the game’s stated rules. Not every audit reaches this level, but it is a requirement under the frameworks used by regulators such as the UKGC.
Security and Compliance Checks
Auditors also review how game software is stored, updated, and protected from interference, and confirm that games meet the licensing authority’s requirements. This includes clear display of rules, RTP figures, and responsible gambling information. Any significant update to a game after certification should trigger re-testing before it is returned to players.
How to Check Whether a Casino’s Games Have Been Audited
Knowing this system exists is one thing. Being able to verify it yourself is what actually protects you. Here are the steps to take.
| What to Check | What It Tells You | Sign of a Problem |
| Certification seal in the website footer | The casino is presenting third-party verification | No seal is visible anywhere on the site |
| Seal links to the auditing body’s own website | The certificate can be independently confirmed | Link is broken or leads to the casino’s own pages |
| Certificate reference number on the auditor’s site | The certificate covers that specific operator | Reference number does not appear in the auditor’s records |
| Casino licence on the MGA or UKGC public register | The operator holds a valid, current licence | Operator cannot be found on the regulator’s register |
| Published RTP performance data | The casino is transparent about actual payout figures | RTP only appears in promotional content with no supporting data |
Most licensed casinos display certification seals at the bottom of their website.
A genuine seal links directly to the auditing body’s own site, where you can look up the certificate by its reference number. If a seal is not clickable, or leads to a page within the casino’s own website, it cannot be treated as verified.
Seals can be copied and displayed by any site without a valid certificate behind them, so following the link and checking the reference number is the only way to confirm a certificate is real.
The MGA and UKGC both maintain public registers of licensed operators. Searching these lets you confirm whether a casino holds a current licence and whether any regulatory action has previously been taken against it.
Why the Casino’s Licence Matters as Much as the Certificate
The auditing framework only works when a credible regulator enforces it. Operators that are unlicensed, or licensed in jurisdictions where oversight is minimal, are not held to the same standards. They may display certification seals or claim independent testing, but without a regulator holding them to account, you have no reliable way of verifying those claims.
This is why the licence a casino holds matters just as much as any certificate it displays. A casino can have a seal and still be operating under a regulator that rarely acts on complaints or enforces testing requirements.
If you want to understand exactly what the MGA requires from operators and why that matters for players, What is the MGA? A Guide to the Malta Gaming Authority explains this in full. And if you are deciding whether an MGA-licensed casino offers meaningfully stronger protection than one licensed elsewhere, MGA Licensed Casinos: Why They Are the Gold Standard sets out the practical differences.
The Limits of Auditing
Auditing gives you strong grounds for confidence, but it is not a complete guarantee of a trouble-free experience.
Certificates reflect when the testing was carried out. Software updates made after that point could affect how a game behaves, which is why ongoing annual auditing matters far more than a certificate that has not been renewed in years.
Standards also differ significantly between jurisdictions. The UKGC and MGA apply some of the most thorough requirements in the industry, while other licensing regimes set a lower bar or do little to enforce the rules they do have.
It is also worth keeping in mind that a game can pass all its technical checks and still be offered by a casino with unclear bonus terms, slow withdrawals, or poor customer support. Auditing confirms fairness at the game level. It is one important piece of evidence, but it should sit alongside your wider assessment of how the operator conducts itself.
Conclusion
When online casino games are audited, accredited independent laboratories test RNG performance, verify RTP accuracy, review game code, and carry out security and compliance checks. The principal auditing bodies are eCOGRA, iTech Labs, and GLI, all of which publish certificates that you can verify directly on their websites.
As a player, the most important thing you can do is not take a casino’s fairness claims at face value. Check for a certification seal, follow the link, confirm the reference number, and cross-check the operator’s licence with the relevant regulator’s public register.
These steps take only a few minutes and give you a clear, evidence-based answer to the question that matters most: can you trust this casino with your money?
