How to Tell If Two Casinos Are Really Sister Sites

What Actually Makes Two Casinos Sister Sites?

“Sister sites” is a useful consumer term, but it is not one single legal category. Two casino brands can be connected in several different ways.

They may be operated by the same licensed company, owned by companies within the same corporate group, run through a white-label arrangement, or use some of the same technical infrastructure.

Those relationships are not identical.

For A2Z, the strongest evidence normally starts with the legal operator and regulatory record, rather than with how similar two websites look.

1. Check the Legal Operator

The first place to look is the licensing statement shown on the casino website.

For Great Britain-facing remote gambling businesses, the UK Gambling Commission requires relevant licensed operators to display their licensed status, account number and a link to their current licensed status.

That means two casinos naming the same licensed company immediately have a much stronger documented relationship than two sites that merely use similar branding.

The legal operator is therefore usually the most useful first comparison.

2. Compare the UKGC Account Number

Next, compare the Gambling Commission account number displayed by each casino.

The account number identifies the gambling business within the UKGC system. If two brands are operating under the same UKGC account, that is strong evidence that the same licence holder is responsible for the regulated gambling activity covered by that record.

However, it is important not to over-interpret this.

A shared UKGC account does not automatically prove that the two brands use the same player login, wallet, bonus system or website platform.

It tells you about the regulatory relationship first.

3. Check the UKGC Domain Records

The UKGC Public Register allows users to search by business name, trading name, domain name or account number.

This makes domain records particularly useful when researching sister-site relationships.

If the domains for Brand A and Brand B both appear within the same operator record, that provides considerably stronger evidence than visual similarity alone.

The Commission also publishes licence status information such as whether a licence is active or expired, while domain and trading-name details are supplied by the gambling business.

Because these records can change, A2Z treats them as dated evidence rather than assuming that a relationship found several years ago remains current today.

4. Check Ownership and Group Relationships

Sometimes two brands are connected even though the immediate legal operator details are not identical.

For example, separate licensed companies may belong to the same wider corporate group.

In those cases, company ownership information and official group disclosures can help explain the relationship.

This is why A2Z separates same operator from same ownership group.

They can both support a sister-site relationship, but they describe different layers of the structure.

For a broader explanation, see Who Owns UK Casino Brands?.

5. Understand White-Label Relationships

White-label casinos require another distinction.

A branded gambling website may have its own consumer-facing identity while the regulated gambling activity is provided under another company's operating licence.

The UK Gambling Commission states that responsibility for compliance across operating gambling websites, including white-labelled sites, remains with the licence holder and cannot simply be transferred to another party.

That creates a meaningful regulatory relationship between brands operating within the same licence environment, even when their marketing identities appear separate.

See our White Label vs Operator Groups Explained for the distinction between these structures.

6. Do Not Confuse Platforms With Ownership

Two casinos can use similar — or even the same — technical infrastructure without being owned or operated by the same company.

A platform can provide technology such as account systems, game integrations, payments, reporting tools or backend functionality to multiple gambling businesses.

The same applies to game providers and payment providers.

Therefore:

• same platform does not automatically mean same operator
• same game provider does not prove shared ownership
• same payment provider does not prove the brands are sister sites
• similar website design is only a weak clue

For more background, see How Casino Platforms Work.

Weak Signals That Do Not Prove a Sister-Site Relationship

Some clues are useful for discovery, but they should not be treated as decisive evidence.

Examples include:

• similar homepage layouts
• the same slot providers
• similar welcome bonuses
• the same payment methods
• similar customer-support interfaces
• matching registration flows
• similar terms-page formatting

These patterns can help identify brands worth investigating, but they should lead to an operator or regulatory check rather than replace one.

This is particularly important because unrelated casinos can use many of the same third-party services.

The A2Z Sister-Site Check

When A2Z evaluates whether casino brands are connected, the process is broadly:

1. Identify each brand and current domain.
2. Check the licensing statement on the live website.
3. Record the legal operator and UKGC account number.
4. Check the domain and trading-name entries in the UKGC Public Register.
5. Check ownership or corporate-group evidence where relevant.
6. Classify white-label relationships separately from direct operator ownership.
7. Use platform, payment and design similarities only as supporting evidence.
8. Date the finding because operator and domain relationships can change.

This approach avoids reducing every casino relationship to a simple “same company” label.

It also allows A2Z to distinguish between current sister sites, historical relationships and brands that simply share technology.