Sierra Casino review 2026: Mirella Ltd, Belize and no stated licence

Sierra Casino has no Gambling Commission licence, and no gambling licence of any kind is stated for it. It is an online casino and sportsbook launched in 2025 for players in Poland and German-speaking markets, operated by Mirella Ltd, a company registered in Belize.

The Gambling Commission register shows no match for Sierra Casino in its lists of businesses, trading names or domains. Two points in this Sierra Casino review matter most: who runs the brand, and a lookalike address that has nothing to do with it.

Who runs Sierra Casino, and where it is aimed

The brand is presented as a combined casino and betting platform for the Polish market and for German-speaking countries. Nothing points to a service built for Great Britain. With no GB licence it does not legally serve players here, and with no licence stated at all there is no regulator named anywhere whose rules it says it follows.

A lookalike domain to be aware of

The obvious .com address for the name is a parked domain unrelated to the brand. That is a small point with a practical lesson: a domain that looks right proves nothing. For a GB licensee, the Commission's register lists the exact domains each account covers, so the safe habit is to start from the register rather than from a search result. This page does not link to the brand.

No GB licence: what it removes

The Commission says GB protections apply "if the business has a Gambling Commission licence". Take the licence away and the age and identity check before play goes with it, as does the GAMSTOP link that blocks all licensed sites at once. So do the £5 slot stake limit (£2 for 18 to 24-year-olds), the 10x wagering cap, the credit card ban and the right to an approved ADR provider when a complaint is not resolved. A Sierra Casino promo code or no deposit bonus would sit outside all of it, which is why none is described here.

Matching a casino to its account number

Every GB-licensed casino states its account number, usually in the footer. Search it on the register, confirm an Active licence covering casino, and match the domain. Our licence check guide shows each step, and the reviews A-Z shows which brands hold a GB licence.

Gambling is for over-18s. GAMSTOP lets you exclude yourself from licensed sites for six months, one year or five years. The National Gambling Helpline on 0808 8020 133 is free, and our responsible gambling page lists more support.