FX Markup Explained: What You're Really Paying on Cross-Border Payments

The Mid-Market Rate

Every currency pair has a mid-market rate — the midpoint between the price at which the market will buy the currency and the price at which it will sell. This is the rate you see on Google Finance, XE.com, or Reuters. It's also called the interbank rate, because it reflects the rate at which banks trade currencies with each other in large volumes.

No retail or business customer pays the mid-market rate. Every conversion involves a spread — the difference between the buy and sell price. The question is how wide that spread is, and how much of it goes to your bank vs how much reflects the underlying market cost.

How Banks Hide FX Markup

Traditional banks rarely present FX fees as a separate line item. Instead, they quote you a "customer rate" — which incorporates their margin invisibly. Here's how to identify it:

• Look up the current mid-market rate for the currency pair on Google or XE.com
• Compare it to the rate your bank is offering
• The difference, expressed as a percentage, is your effective FX cost

For a UK business sending £100,000 to a EUR supplier at a bank rate 2% below mid-market, the invisible cost is £2,000 — on a single transaction. Multiply that across a year of regular international transfers, supplier payments, or currency collections, and FX markup is often the largest single cost line that businesses have never reviewed.

What Makes Up Your FX Cost

Your total FX cost has up to three components:

1. The Spread

The spread is the margin between the buy and sell rate. For major currency pairs like EUR/GBP and USD/GBP, the true market spread is tiny — a fraction of a basis point for large transactions. What banks quote as their "spread" is almost entirely their margin. Exotic or emerging-market currencies have genuinely wider underlying spreads, so FX costs in currencies like PLN, CZK, or BRL will be structurally higher regardless of provider.

2. Commission or Transfer Fee

Some providers charge an explicit commission or transfer fee in addition to the rate markup. This might be a flat fee (e.g. £15–40 for a SWIFT transfer) or a percentage commission on top of the rate. The combination of a marked-up rate and an explicit transfer fee is common at traditional banks. FX specialists and fintechs typically charge one or the other, not both.

3. Correspondent Bank Fees

For international SWIFT payments, correspondent banks in the payment chain may deduct fees from the transferred amount. Your bank may quote the send amount correctly but a correspondent bank en route may take £10–30 before the payment arrives. This is more common on payments to Africa, parts of Asia, and Latin America. Local payment rails (SEPA, Faster Payments, etc.) avoid this entirely.

Dynamic Currency Conversion (DCC) — What to Avoid

DCC occurs when a card terminal or online checkout offers an international cardholder the option to pay in their home currency. For example, a German customer on your UK website being offered "Pay in EUR or GBP?"

For the customer, DCC almost always means a worse rate — the DCC provider's markup is typically 3–5% above mid-market, presented as "convenience." For the merchant, it can generate a small revenue share but almost always leads to customer complaints and, more seriously, chargeback risk when customers realise they overpaid.

Unless your business has a specific commercial reason to offer DCC, disable it in your payment terminal and gateway settings.

How to Benchmark Your FX Cost

Measuring your current FX cost requires two data points: the mid-market rate at the time of each conversion, and the rate you were actually given. Most banks and PSPs don't provide this automatically — you need to track it manually or use a third-party tool.

A simpler approach for benchmarking purposes: take your largest regular FX transaction type (e.g. monthly EUR supplier payments), look up the mid-market rate at the time of the last five conversions, and compare to the rates in your bank statements. If you're paying more than 1% above mid-market on major pairs, you're overpaying.

How to Reduce FX Costs

• Use a specialist FX provider or fintech. Wise Business, Airwallex, Currencycloud, and similar providers routinely charge 0.1–0.5% above mid-market versus the 1.5–3.5% charged by traditional banks. The account setup is straightforward and integration with existing business banking is usually seamless.
• Hold funds in the collection currency. If you collect USD from US customers, hold those USD and pay USD-denominated suppliers directly. Converting USD → GBP → USD twice removes value both times. A multi-currency account eliminates this entirely.
• Convert in bulk. FX providers typically offer better rates for larger individual conversions. Converting £50,000 once is cheaper (percentage-wise) than converting £5,000 ten times. Batch your requirements where possible.
• Negotiate an explicit rate. For regular, predictable FX requirements above £50k/month, ask your provider for a named rate rather than accepting their published rate. Most specialist providers will negotiate for accounts of this size.
• Use local payment rails. Receiving EUR via SEPA and paying EUR via SEPA avoids SWIFT altogether, cutting correspondent bank fees to zero and often settling faster.