That denominator can remove taxes, payment costs, platform fees, promotions, chargebacks, fraud and other items. It can also change from one programme to another. The headline percentage is therefore only one line of the commercial deal; the definition underneath it decides what the percentage is worth.
This explainer compares public terms from Gamesys Group Partners and Betfair Affiliates as opened on 20 September 2026. It does not describe a private deal, recommend either programme or replace contract, tax or legal advice.
The percentage comes last
The cleanest way to read a revenue-share agreement is backwards. Start with the payment, divide by the agreed rate, and ask which revenue number the operator used. Then trace every movement between gross and net.
Our GGR versus NGR explainer separates stakes, player winnings and later deductions at company-reporting level. An affiliate agreement adds another boundary: only the customers attributed to that affiliate—and only the products, period and events covered by the contract—enter its commission statement.
Consider a fictional month. These numbers do not reproduce either operator's statement or suggest a normal rate.
| Illustrative line | Amount | What it shows |
|---|---|---|
| Contract-defined gross revenue | £100,000 | The starting base for the example |
| Permitted deductions | £25,000 | Tax, fees, reversals or other items allowed by the fictional contract |
| Commissionable net revenue | £75,000 | The amount left before the share is applied |
| Revenue share at 30% | £22,500 | 30% of £75,000, not 30% of £100,000 |
Change the permitted deductions from £25,000 to £10,000 and the same 30% headline produces £27,000. No rate changed. The denominator did.
“Net” is not a standard basket
Gamesys Group Partners' public terms, last updated 31 January 2025, define Affiliate Revenue Share as a percentage of Net Gaming Revenue. Their NGR definition begins with Gross Win, then lists deductions including finance fees; licence fees and gaming taxes; third-party licence and platform fees; a charitable allocation; operating and administration costs; and revenue linked to invalid, criminal, fraudulent or disputed payments and some refunds.
The same document defines Finance Fees to include payment processing on deposits, withdrawals and winnings, chargebacks and KYC verification fees. That placement matters: one apparently simple line on a statement can aggregate several operating events before the reader ever reaches the final commission calculation.
Betfair's public terms, marked “Last Updated: December 2020”, use Net Revenue as an aggregate of product-specific measures: fixed odds, multiples, exchange commission, casino, poker and other products. The deductions are embedded in those individual definitions. Depending on the product, the document names items such as chargebacks, fraudulent or voided transactions, bad debt, promotional costs, sports-body payments, hedging costs, duties, data-licensing fees and third-party software costs.
The labels look similar but the construction is not. A reviewer cannot safely move one programme's NGR formula into another programme's spreadsheet.
Negative revenue is a second commercial term
A cohort can produce a negative month when player winnings and allowable costs exceed the covered revenue. The question is what happens next.
Gamesys' commission provisions say the commission balance is reset to zero at the beginning of each calendar month so a negative balance is not carried forward. The same public terms specify payment thresholds that vary by method, including £25 for a UK bank transfer and £200 for an international bank transfer. Payment is due within 30 days after Gamesys receives a valid, undisputed invoice at the correct address.
Betfair takes a different position in its revenue-share and payment clauses. If a month's revenue share is negative, Betfair says it may carry that amount forward and set it against later revenue share, but may instead reset it to zero. Its public threshold is more than £50 or the currency equivalent, and the terms state that payment is made within 60 days of month-end unless agreed otherwise.
Betfair's affiliate FAQ also warns that negative revenue on profit-and-loss products can affect the following month's commission. The contract remains the controlling document; a help page is useful context, not a substitute for the applicable agreement and account-specific commission page.
This is why “no negative carryover” belongs beside the percentage in any commercial comparison. It can be more consequential than a small difference in the advertised rate.
Attribution can change the base before deductions
Even a perfectly itemised deduction report can start from the wrong population. Revenue share depends on which customers the tracking system attributes, for how long, on which products and after which qualifying action.
Betfair's public terms, for example, describe a standard two-year customer-expiry period for revenue share while also allowing other commission options and account-level changes. A private insertion order might define a different cohort, territory, product or term. Cookie windows, cross-device journeys and duplicate accounts can create operational differences before finance calculates net revenue.
That is one reason gambling groups value media and affiliate operations for more than a stream of links. Our report on why gambling groups buy media and affiliate businesses follows the audience, technology and recurring-revenue logic behind those deals. The quality of attribution data affects both monthly statements and the valuation of the asset producing them.
A statement should reconcile, not merely announce
The useful monthly pack lets an affiliate move from attributed customer activity to payment without inventing a missing subtotal. At minimum, the contract and statement together need to identify:
the covered customer cohort, products, currency and period;
the gross measure and where bonuses or player incentives enter it;
each permitted deduction category and any allocation method;
adjustments for fraud, voids, refunds, bad debt and chargebacks;
the negative-balance rule, minimum threshold and payment timing;
later corrections, overpayment recovery and the contract version in force.
A chargeback deserves special attention because it can be recognised after the original deposit month. Our payment-stack guide to gambling chargebacks shows how an issuer dispute, network process and operator ledger move on different clocks. The affiliate question is narrower: when does the agreement permit that reversal to reduce commission, and can a later correction reopen a paid period?
The same audit discipline used in iGaming payment reconciliation helps here: keep the provider reference, internal event and settlement line connected rather than forcing several states into one label.
Neither public programme makes an affiliate's dashboard an immutable ledger. Betfair's terms reserve a right to correct calculation errors and reclaim overpayments. Gamesys can withhold amounts in specified suspicious-activity, breach and compliance circumstances. A sensible reconciliation therefore preserves the statement, raw export, invoice, contract version and any manual adjustment note for the same period.
Compliance is part of the relationship, not a deduction label
Not every commercial risk appears in the NGR waterfall. In Great Britain, Gambling Commission code provision 1.1.2 makes licensees responsible for contracted third parties and requires contractual controls, including a route to terminate affiliates that breach relevant advertising codes.
The Commission's third-party responsibility guidance also calls for due diligence, oversight and controls over contracted activity. Those are obligations around the relationship; they are not permission to invent a deduction absent from the commission agreement.
That rule does not turn compliance work into an automatic NGR deduction. It explains why affiliate contracts contain monitoring, approval, information and termination duties alongside the payment formula. A breach can lead to withheld amounts or termination only where the applicable agreement and law allow it; it should not be smuggled into an unexplained line called “other costs”.
The commercially useful question is not “What is the revenue-share percentage?” It is: percentage of which defined revenue, for which tracked customers, after which deductions, with what treatment of negative months and corrections? Until those five parts reconcile, the rate is a headline rather than a price.
