Verdict
Verdict at a glance
- Sister sites share an operator or an owner. Casino alternatives share neither (Gambling Commission register, as of October 2026).
- A shared licence carries a shared new-customer test, a shared complaints route and shared operator-level self-exclusion (operator terms, verify against live terms).
- GAMSTOP covers every UK-licensed brand, so a registration applies to sisters and alternatives alike (Gambling Commission licence conditions).
- Single pick by use case: choose a sister site for shared terms and tools, and an alternative when an existing account blocks a welcome offer.
Sister sites defined
A sister site is a casino brand that shares an operator or an owner with another brand. The Gambling Commission register lists each licence holder with the web addresses covered, so the register decides which brands qualify (as of October 2026). Jupiter Gaming Limited is a worked case. Its licence covers 7 active domains, including kingcasino.com, mrluck.com and redcasino.com, and those 7 brands are same-operator brands.
The label has limits. Sister site is a search term and not a legal category. Brands under 1 parent company but on separate licences are related by ownership only. Each licence holder sets its own terms (Companies House, persons with significant control filings). Not surfaced from the register: a parent company for Jupiter Gaming Limited.
Casino alternatives defined
A casino alternative offers a similar product from a different company. Nothing is shared beyond the style of the offer. Matching lobbies, bonuses and cashier screens come from shared software suppliers, and they aren't evidence of shared rules. A brand on another licence holder's licence is an alternative to the Jupiter Gaming brands even when the lobby looks the same.
Differences compared
| Point | Sister sites | Casino alternatives |
|---|---|---|
| Licence holder | Same operator, or same owner | Different company |
| New-customer test | Shared when the licence is shared (verify against live terms) | Separate |
| Operator-level self-exclusion | Applies across the operator's brands (operator terms) | Separate |
| GAMSTOP | Covers every UK-licensed brand | Covers every UK-licensed brand |
| Complaints route | 1 operator | Separate operators |
| Welcome offer | Set by each brand | Set by each brand |
The pattern follows 1 mechanism. Licence conditions attach to the licence holder and not to the brand name. A new-customer clause, an exclusion list and a complaints desk sit with the company. Brand-level details such as the welcome offer sit with each brand.
The table shows the default pattern, and wording varies by operator. Some new-customer clauses name the brand, others the operator, the household or the payment method (operator terms, verify against live terms). A second welcome offer at a sister brand needs a check of that clause before registering.
A sister site doesn't reset a self-exclusion
A sister site doesn't reset a self-exclusion. GAMSTOP covers every UK-licensed operator (Gambling Commission licence conditions), so your registration applies at every sister brand and at every alternative that holds a UK licence. An exclusion set directly with a casino applies across that operator's brands (operator terms, verify against live terms).
What this means in practice: a brand that accepts a registered player isn't meeting UK licence conditions, or isn't UK-licensed. If you've set a deposit limit at 1 brand, set the same limit at each sister before you deposit. We couldn't confirm that 1 limit carries across a group, so assume it doesn't.
If gambling is causing you problems, free support is available from GamCare and BeGambleAware. You can register with GAMSTOP at no cost. Commission from operators is disclosed at the top of this page, and it doesn't change the advice above.
Use-case shortlist
- Same terms and tools across brands. Pick: Sister site; Basis: 1 licence holder, 1 complaints route
- Welcome offer blocked by an existing account. Pick: Alternative; Basis: Separate new-customer test (verify against live terms)
- Distance from an operator with an enforcement record. Pick: Alternative; Basis: The record attaches to the licence holder and every brand under it
Final verdict
The licence holder decides the answer. Brands under 1 licence holder are sisters, and brands under different licence holders are alternatives. The register entry settles the question, and the footer licence number points to it.
Readers who want the check itself can follow How to find a casino's operator. The Jupiter Gaming operator profile shows the 7 brands used above. For the ownership layer behind a group, see Casino groups and white labels explained.