The visible cost: processing fees
Processing fees are the percentage and fixed-fee charges you see on every payout. For a typical SMB they make up 70 to 90 percent of total payment cost. They are the easiest part to compare, which is why most provider comparisons stop there.
If you are reading your monthly statement and looking only at the processing fee line, you are looking at most but not all of the cost.
Refunds — the cost depends on policy
When you refund a sale, two things happen. The customer gets the original transaction value back. Depending on the provider, the percentage processing fee may or may not be returned to you. Many providers keep it.
On a refund-heavy business — apparel, electronics, anything with sizing or fit issues — this adds up. A merchant with 8 percent refund rate on 50,000 monthly volume loses roughly 100 a month in unrecovered processing fees alone, on top of the refunded revenue.
Chargebacks — small per case, large in the tail
Chargebacks are not the same as refunds. A chargeback is initiated by the cardholder via their bank, not by you. Each one carries a fixed fee of 15 to 25, regardless of outcome. The original transaction value is held back during the dispute.
Beyond the per-case cost, an elevated chargeback rate (above roughly 0.9 to 1 percent) puts you on a card-network monitoring programme that can mean higher base rates or, at the extreme, account closure. The tail risk is much larger than any individual chargeback fee.
FX margin — the silent international tax
If your transactions are in a different currency from your settlement currency, the provider applies a currency conversion margin. It is often 1 to 4 percent above the interbank rate, depending on provider.
This rarely shows up as a separate line on the statement — it is netted into the payout amount. The only way to see it is to compare the gross transaction value to the settled amount on a sample of cross-currency transactions.
Operational time — the cost no statement shows
Reconciling payouts, responding to chargeback evidence requests, fighting refund disputes, and integrating new providers all take time. For a small business owner whose time is the binding constraint, an extra hour a week on payments operations is real money.
Choosing a provider with poor dispute tools to save 0.2 percent in fees is often a bad trade. The fee saving is visible; the time cost is not, but the latter compounds the same way.
A practical example of total cost
An online shop processes 30,000 monthly volume across 250 transactions. AOV: 120. International share: 25 percent. Refund rate: 4 percent. Chargeback rate: 0.3 percent.
Processing fees at a 2.9 + 0.30 rate: roughly 945 a month. Plus international surcharge: 110. Plus FX margin on cross-currency transactions: 60. Plus unrecovered refund fees: 35. Plus one chargeback at 25. Total real cost: 1,175 a month — 24 percent higher than the processing fee line alone.