Ask a CFO how much their bank charges for foreign exchange, and most will say something like “not much” or “whatever the standard rate is.” Ask them to put an actual number on it, and the conversation usually stops there.
That’s not a knowledge gap, more like a design feature. Most FX margin isn’t charged as a fee; it’s built into the exchange rate itself, so there’s nothing to query on a statement and nothing that ever appears in a board pack. No invoice arrives labelled “currency margin.” The cost simply sits within a number that, at a glance, looks like an ordinary exchange rate.
An FX fees comparison between a typical bank and a specialist provider – the hidden FX fees most businesses never see itemised – often looks small in isolation: 0.5% versus 3%, say. It’s the kind of difference that’s easy to wave away on a single payment. Across a year of regular international payments, it isn’t small at all, and recent research suggests most UK businesses are feeling exactly this kind of squeeze without necessarily being able to name it.
Where the Percentage Actually Comes From
When a business converts currency, there are two ways a provider can charge: a visible fee or a margin built into the exchange rate. Most high-street banks lean heavily on the second option, because it’s far less visible and far less likely to be questioned. This is really where any genuine FX fees comparison has to start – not with the fee, but with the rate itself.
A typical bank exchange rate margin sits somewhere around 2.5 to 3% above the mid-market rate, the real, tradeable rate you’d see quoted on a source like XE, Google or Reuters at any given moment. Whereas a specialist FX provider, competing directly on rate rather than relying on an existing banking relationship, typically operates closer to 0.3 to 0.5%.
On paper, that’s a difference of roughly 2.5 percentage points. It doesn’t sound dramatic. However, the scale of it only becomes clear once it’s applied to actual payment volume, rather than viewed as an abstract percentage on a rate sheet.
It’s worth being clear about what this percentage actually represents. It isn’t a transfer fee, a wire charge or an administration cost. Those tend to be small, visible and easy to compare between providers. The margin is different: it’s the gap between the rate you’re quoted and the rate that genuinely exists in the market at that moment.
Two providers can both advertise “no transfer fee” and still charge wildly different amounts, because the real cost was never in the fee to begin with, one quietly taking six times more out of every payment than the other, despite looking identical on the surface.
This isn’t a small-scale problem either. Independent research found that 54% of UK SMEs trading overseas had been hit by currency volatility in the past year, losing an average of more than £53,000, with the smallest firms hit hardest. While most of that is genuine market movement, a meaningful share is simply margin quietly compounding, unnoticed until someone adds up a full year in one place.
A Worked Example: £50,000 a Month in Overseas Payments
Take a business paying an overseas supplier £50,000 a month, a common volume for a growing SME with regular international costs. Here’s what that FX fees comparison looks like in practice, side by side.
| Bank margin (3%) | Specialist provider (0.5%) | |
| Cost per £50,000 payment | £1,500 | £250 |
| Monthly cost | £1,500 | £250 |
| Annual cost | £18,000 | £3,000 |
The difference isn’t the £1,250 shown as a single payment. It’s £15,000 a year, money that never appears as a cost on any invoice, because it was never charged as one. It simply reduces the amount that reaches its destination, payment after payment, without ever being flagged.
For a business making smaller or larger transfers, the same principle applies in proportion. A business converting £20,000 a month at the same margins would still be losing roughly £6,000 a year. One converting £150,000 a month would be looking at a gap closer to £45,000 a year. The percentage stays constant; only the scale of what it’s quietly costing changes.
These figures are illustrative rather than a quote for any specific business, since actual margins vary by provider and currency pair, which is exactly why calculating your own number matters more.
Is Your Business Absorbing This Without Realising It?
If you’re regularly converting currency and haven’t recently checked your actual bank exchange rate margin against the mid-market rate, there’s a reasonable chance the answer is yes.
Book Your FX Strategy Review to see the real number for your business, not an estimate.
How to Calculate Your Own Number
The example above shows one FX fee comparison. Most businesses’ actual exposure looks nothing like a tidy round figure, so it’s worth working out the real one rather than relying on someone else’s example. The calculation itself is straightforward and can be done with information you almost certainly already have.
First, find the mid-market rate for your currency pair at the time of a recent transfer. A quick search of the currency pair on XE, Google or Reuters, for example “GBP EUR”, will show it, and most of these sources show a timestamp on historic rates too.
Second, compare it to the rate you actually received on that transfer, which should be visible on your statement or confirmation email.
Third, calculate the percentage difference between the two. That’s your real margin, regardless of any fee quoted separately alongside it.
Fourth, multiply that margin by your annual international payment volume to see the full-year figure.
The result is usually the first time a business has seen this cost expressed as a single annual figure, rather than buried inside dozens of individual transactions spread across twelve months of statements.
BLK Insight
To make that annual figure easier to place in context: £15,000 a year is roughly the cost of a part-time finance hire, a year of the average SME’s software stack, or a meaningful dent in a training and development budget.
None of that money has gone anywhere useful; it’s the classic shape of hidden FX fees. It’s simply the gap between two exchange rates, absorbed silently, transaction by transaction, month after month.
Businesses reviewing this for the first time are often less surprised by the size of the number than by how long it took to notice it. Finance teams that would query a £500 discrepancy in almost any other part of the business have, in many cases, been letting a far larger one pass unchecked simply because it was never presented as a single figure.
Why the Gap Persists, and What Closing It Actually Takes
If the difference is this significant, it’s fair to ask why more businesses haven’t already switched providers or renegotiated terms. The honest answer usually comes down to three things:
- The cost is invisible by design, with no line item labelled “FX margin” to prompt a review.
- The banking relationship predates the need, having been set up long before international payments became a regular part of the business, with FX never renegotiated as volumes grew.
- “Not much” genuinely feels true on any single transaction, only becoming hard to ignore once a full year of volume is added up in one place.
None of this is a criticism of the businesses involved; it’s simply how the system is built to be overlooked.
Closing that gap isn’t about negotiating harder with an existing bank. Most high-street providers aren’t structured to compete meaningfully on FX margin. It isn’t their core business; it’s a byproduct of a much wider relationship built around lending, deposits and day-to-day banking.
Getting closer to 0.5% typically means working with a provider whose core business is foreign exchange itself, where a competitive rate is the actual product on offer, not an incidental add-on to something else. That distinction tends to explain the true cost of international payments far better than any single negotiation ever could.
Ready to See Your Actual Number?
The example above uses £50,000 a month. Your actual figure could be higher or lower, or spread across several currencies, but it’s worth knowing exactly what it is rather than estimating it.
Book Your FX Strategy Review and see the real gap between what you’re paying now and what’s actually possible.
