How We Rate

Last updated: 26 July 2026

This page sets out, in full, how The Best Slots Sites scores and ranks the casinos, slots, bonuses, and providers listed on this site. See About Us for a shorter summary and Editorial Policy for how the underlying reviews are researched and written.

Casino ratings

Every casino review shows two figures: a score out of 10 and a star rating out of 5. Both are built from the same underlying assessment, not sold or negotiated with the operator. We weigh:

• Current UK Gambling Commission licence status — a hard requirement, not just a factor (see below)
• The fairness and clarity of bonus terms: wagering requirements, game weighting, expiry windows, and withdrawal conditions
• The range and reliability of UK payment methods and withdrawal speed
• Game selection and the quality of the software providers on offer
• Player-facing support: deposit limits, self-exclusion tools, and responsible gambling features

We do not accept payment for a higher score or star rating. Where an operator is one of The Best Slots Sites's own brands, it is assessed against exactly the same criteria as a partner brand — see Editorial Policy for our independence disclosure.

Slot ratings

Each slot's score out of 10 is built from:

• Its published RTP (return to player) tier — we reference the full range where a provider publishes one
• Volatility rating
• Maximum win multiplier
• The range and depth of its bonus features
• The track record of the software provider that built it

We source these figures from the provider's own published game data wherever it's available — cited at the bottom of the review — rather than third-party aggregator figures. We never invent a specific numeric claim we don't have a real source for; where a figure can't be verified, we describe it qualitatively or leave it out entirely.

Bonus rankings

The Bonusespage ranks operators by the same overall casino score described above — there isn't a separate, bonus-only scoring formula. Bonus-term fairness (wagering requirements, game weighting, expiry, withdrawal conditions) is one of the components that feeds that single score, so a large headline offer with unfavourable terms won't outrank a smaller, fairer one. Every offer shown carries its key terms next to the headline, not just a link to full T&Cs — see our compliance approach on About Us. Offer details are supplied by the operator and can change after we publish; we periodically re-check live offer pages, and the operator's own terms always take precedence over our summary.

Provider pages

Software providers (e.g. Pragmatic Play, NetEnt) are not given a star rating or score — a provider's catalogue is too varied for a single number to mean much. Instead, each provider page shows factual details (founding year, headquarters, licences/certifications where public) alongside aggregate statistics computed from that provider's own slots we've reviewed: average and range of RTP, hit frequency, and maximum win multiplier across their catalogue, plus their highest-scoring titles. These are descriptive, not a ranking against other providers.

What keeps an operator off this site

We only list and promote operators that meet all of the following. Any one failure is disqualifying:

• Holds a current UK Gambling Commission licence — no licence, no listing, regardless of offer size
• Publishes clear bonus terms — we won't list an operator whose wagering requirements, game restrictions, or withdrawal conditions are deliberately obscured or contradicted between their site and their T&Cs
• Offers a working UK payment and withdrawal path
• Provides accessible responsible gambling tools (deposit limits, self-exclusion, GAMSTOP registration)

An operator that loses its licence, or is found to be materially misrepresenting its terms after we've published a review, is removed or re-scored — see the Freshness section of our Editorial Policy for how often we re-check live listings.