How we source data and compare offers
Updated 26 October 2026 · Editor: Nigel Hall
SlotSitesUK combines Gambling Commission records with the terms casinos publish on their own websites. This page explains how those sources become casino profiles, operator pages and the welcome-offer comparison.
Building the operator and casino directory
Our starting point is the Gambling Commission’s business register and its downloadable records. We use licence-account identifiers to connect operators, licence records, trading names and registered domains. The casino-facing directory is drawn from relevant consumer casino records rather than treating every business in the register as an online casino.
An operator account number and an individual licence number are different identifiers. A trading name or registered domain is also not a separate licensed company. We aim to preserve these distinctions. “Sister sites” means brands connected to the same recorded licensed operator; it does not by itself establish the ultimate corporate owner, identical terms or shared eligibility for a promotion.
The register includes historical and inactive information. Appearing in our directory does not prove a business is currently accepting customers. An unsuccessful website visit is not evidence of closure or licence suspension. A licence change needs a corresponding official record.
Collecting casino information
The collector starts from a registered casino domain and follows relevant public links, including promotion indexes, individual campaign terms, general terms, payment information and help pages. Browser rendering helps reveal content loaded after the initial page response. The process can open public terms panels and read accessible page content without creating a casino account or depositing money.
For each source, we retain a dated record and a content fingerprint. Relevant source material is processed into separate facts and promotions. We preserve the supporting text and source addresses internally, while public profiles organise the information into readable sections. Full promotion terms remain linked from the relevant offer.
A publicly visible catalogue total is reported with its scope: an approximate count of all casino games is not an exact count of slots. A named provider is not proof that every game from that provider is available. Deposit methods and withdrawal methods are recorded separately, as are operator processing estimates and payment delivery estimates.
What the collector can and cannot see
We seek both welcome offers and public promotions for existing customers. Selected-customer or app-only eligibility must be made clear when the public terms establish it. We do not sign into private accounts to invent a supposedly universal offer from a personalised promotion.
Access restrictions, geographical differences, temporary errors and changes in page layout can prevent a successful check. Browser rendering does not guarantee access to every offer. No promotion in a profile should be read as proof that the casino has no promotions. Missing details do not mean a restriction is absent.
Check dates and publication
The monitoring queue works through sources on the configured schedule. New and changed material can require further processing before a profile changes. Browser visits, successful page records, published casino profiles and published offers are different counts: checking several pages for one casino does not mean several casinos have been completed.
An offer’s update date identifies the published record’s latest successful check. It is not a promise that every offer has been checked today. Where the system detects an expired offer, a failed freshness check or a change that has not yet been processed, that offer can be withheld from the current comparison. Readers should check the casino’s full terms before deciding whether to participate.
Recording changes over time
We compare successful observations and retain previous versions of offer details. This can reveal changes in the reward, deposit, wagering requirement, deadline or other material conditions. The history begins with our first observation. It cannot establish what a casino offered before monitoring began, or the precise time of a change between two checks.
General terms can change without a welcome-offer headline changing. Those records are kept separately where monitored. A wording change is not automatically treated as a new restriction or evidence of misconduct; the meaning and context matter.
How the welcome-offer comparison works
The main comparison normally shows one welcome offer per casino, with a link to additional promotions on its profile. Existing-customer campaigns, tournaments and prize draws belong in their own context. Selected-customer offers are not presented as generally available welcome bonuses.
The rating considers published reward value, required deposit and stakes, wagering conditions, winnings limits, deadlines and restrictions. Wagering is assessed with its stated basis: a multiplier on bonus funds differs from one on deposit plus bonus. The nominal value of spins describes an amount of play, not cash a reader is guaranteed to receive.
Where some conditions cannot be established, the rating is constrained rather than treating the unknown condition as favourable. An offer with too little usable information may have no numerical rating. The overall number must be read alongside the significant conditions, eligibility and full terms.
Regulatory action and ratings
Recent dated financial penalties and regulatory settlements can reduce an offer’s assessment when the official decision is linked to its operator account. We distinguish the decision date, the stated outcome and the published reasons. Relevance, recency and repeated action matter; an old fine is not automatically a permanent deduction.
Historical action does not itself mean the operator is suspended today. Equally, no adjustment is not a certificate of a clean regulatory history: a decision may not yet be in our records. Operator pages provide the context and links to the official decisions available to us.
What the badges mean
The leading rated entries in the current welcome-offer comparison receive numbered top-five badges. They identify positions among the eligible offers displayed in that comparison, not the five best casinos in the entire market. They are not awards from the Gambling Commission or promises about a reader’s outcome.
Ratings and positions can change when terms change, better information becomes available, a correction is made or the assessment policy is revised. Affiliate commission is never an assessment factor. For editorial independence and corrections, read our editorial policy or email contact@slotsitesuk.com.