Interchange Fees Explained: What Every Singapore Merchant Should Know

An interchange fee is a per-transaction charge that flows from the merchant's bank (the acquirer) to the customer's bank (the issuer) whenever a card payment is made. Think of it as a cost-sharing mechanism built into the card network: the issuing bank takes on credit risk, handles fraud disputes, and funds rewards programmes, so the interchange fee is its compensation for those services.

As a merchant, you don't pay the interchange fee directly to the issuing bank — it is bundled into the overall rate your payment provider charges you. But it is still the single largest component of that rate, so it directly influences how much card acceptance costs your business. Debit card transactions tend to carry lower interchange fees than credit cards, and plain credit cards usually cost less than premium rewards cards — the bank is passing on the cost of those air miles or cashback it promises to cardholders.

Interchange rates are set by the card networks — Visa, Mastercard, and others — not by your payment provider. The networks publish detailed rate schedules, but these schedules can run to dozens of categories, which is why merchants rarely see a single, simple number.

Several variables determine which rate applies to any given transaction. Card type matters most: a basic debit card sits at the lower end, while a premium travel rewards credit card sits at the higher end because the issuer needs to fund the rewards it promises. Merchant category also plays a role — the network categorises your business with a Merchant Category Code (MCC), and certain MCCs (groceries, fuel, non-profits) receive preferential rates. Geography is another driver: domestic transactions, where both the merchant and cardholder are in the same country, typically attract lower interchange than cross-border or international transactions. Finally, transaction method matters — a card physically tapped or inserted at a terminal is verified differently from an online card-not-present transaction, which carries higher fraud risk and therefore a higher interchange rate.

Merchants pay a single blended rate called the Merchant Discount Rate (MDR). The MDR is built from three layers: the interchange fee (the issuing bank's share), the scheme fee (Visa or Mastercard's network fee), and the payment provider's margin (covering their platform, support, and profit). Understanding this breakdown explains why MDR rates differ across providers and across card types even on the same platform.

Most small and medium businesses in Singapore use bundled or flat-rate pricing, where the provider collapses all three layers into one predictable percentage. This is simpler to budget and means you don't need to track which card type each customer uses. Interchange-plus pricing — where the interchange is passed through at cost and the provider adds a fixed markup — offers more transparency but introduces variability that can make forecasting harder. For most growing businesses, the predictability of flat-rate pricing is the more cost-effective choice day to day. See the merchant discount rate glossary entry for a deeper look at how MDR is calculated.

Singapore merchants operate in a market where a significant share of customer payments come via international cards — tourists, expats, and cross-border e-commerce buyers all contribute. International card transactions typically carry a higher interchange component than domestic ones, and that difference feeds through into the MDR you pay.

With ONE, you get a transparent flat rate that removes the guesswork: domestic card transactions are priced at 2.7% + USD 0.50, and international card transactions add 0.7%, coming to 3.4% + USD 0.50. There is no setup fee and no monthly fee, so you only pay when you process a transaction. This all-in-one pricing means that regardless of whether a customer pays with a domestic debit card or an international premium rewards card, you know exactly what you will be charged. For businesses with a strong international customer base, this predictability is especially valuable — you can price your products and services with confidence rather than guessing at your net margin after fees. Check out the full payment processing fees breakdown for a side-by-side comparison.

While you cannot negotiate interchange rates directly with card networks, there are practical steps that help you manage and minimise their impact on your bottom line.

First, ensure your MCC is correct. If your business is miscategorised, you may be paying a higher interchange tier than necessary. Ask your payment provider to confirm your MCC matches your actual business activity. Second, favour card-present transactions where possible. Physical terminal payments — tap, chip, or swipe — are authenticated differently from online or manually keyed transactions and generally attract lower rates. If you run both an online store and a physical location, this distinction matters. Third, choose a pricing model that suits your volume. Flat-rate pricing (like ONE's) removes interchange variability entirely and works well for most businesses. As your volume grows, it's worth asking your provider about volume-based arrangements. Finally, keep an eye on dispute rates — high chargeback ratios can trigger penalty tiers and additional fees that compound your processing cost. A clean dispute record is one of the simplest ways to simplify payments and keep costs stable over time.

Regulated payment services are provided by Airwallex (Singapore) Pte. Ltd., a MAS-licensed Major Payment Institution under the Payment Services Act 2019. ONE Payments acts as a technology provider and merchant service facilitator.

The information in this article is intended for general educational purposes and does not constitute financial or legal advice. Interchange fee rates, card network rules, and regulatory requirements may change over time — always verify current rates and terms directly with your payment provider or the relevant card network. Businesses with specific compliance queries, particularly around cross-border payment flows or high-volume processing arrangements, should seek independent professional guidance. ONE Payments is committed to providing transparent, cost-effective payment solutions to help Singapore businesses simplify payments and manage their costs with confidence.