Separate the percentage of payment value from flat charges. Then check what triggers each charge: an attempt, an authorisation, a capture or a successful payment.
In practiceA 0.20 flat fee is 4% of a 5 payment, but only 0.2% of a 100 payment.
A combined percentage, often with a flat fee. Check the scope: different cards, markets and services can carry additional charges.
payment value × rate + flat feeInterchange, scheme fees and the acquiring markup are shown separately. Their billing bases can differ; flat charges may also apply.
interchange + scheme + markupA charge per billable payment or event. Its effective percentage changes with ticket size; minimums and subscriptions can matter.
billable events × feeHow processing fees and method-specific charges fit together. Check the relevant market and your contract.
Processing · Payment methods · IC++A starting point for checking standard pricing, additional products and custom-pricing conditions in your market.
Standard pricing · Add-ons · Market scopeWhy issuing a refund and receiving the original processing fees back are separate questions.
Refunds · Retained feesExplore fee categories and billable events when reconciling a processing invoice.
Invoices · Attempts · Other servicesMerchant and issuer countries, card or method types, channels, currencies and the date the terms apply.
Per attempt, authorisation, capture or settlement? Check retries, reversals, failed payments and minimum invoices.
Confirm treatment of authentication, fraud tools, tokens, reporting, terminals, support and payout charges.
Identify retained original fees, refund fees, dispute fees, fee reimbursements and principal liability.
Check the conversion reference, spread, cross-border fees, payout timing, calendar conventions and reserves.
Check tiers, commitments, monthly minimums, pass-through charges and how price changes are communicated.
Test a lower rate against a higher fixed fee. Add refunds, conversion or slower settlement. Use your own numbers to see which assumptions matter most.