Key takeaways
- Published UK rate cards read on 19 August 2026 charge 0.03% to 0.99% to convert sterling on the first slice of a trade, a spread of 33 times.
- Pay in £500 a month for 20 years, £120,000 of contributions, and the dearest of those rates takes £1,188 in foreign exchange fees against £36 at the cheapest.
- One 0.99% conversion held for 20 years works out at 0.05% a year, while Vanguard's account fee of 0.15% a year adds up to 3% across the same stretch.
- Hargreaves Lansdown adds a spread of 1% converting dividends. On the S&P 500 index dividend yield of 1.13% at 31 July 2026, that costs 0.0113% a year.
- Vanguard's FTSE All-World UCITS ETF reported transaction costs of 0.03% as at 31 December 2025, and that figure already contains foreign exchange costs nobody itemises.
Foreign exchange fees run from 0.03% to 0.99% on the first slice of a trade
You want to buy a US share through a UK platform, and you want to know what the currency conversion charge is. Here's the answer from rate cards read on 19 August 2026. Hargreaves Lansdown charges 0.99% on the first £10,000 of a trade, 0.50% from £10,000 to £25,000, and 0.20% above that. AJ Bell charges 0.75% on the first £10,000, 0.50% on the next £10,000 and 0.25% on value over £20,000, on a schedule in force from 1 May 2026. Interactive investor charges 0.75% on its Core plan and 0.25% on Premium. Freetrade charges 0.99%, 0.59% or 0.39%, depending on the plan. Interactive Brokers adds 0.03% to the exchange rate when it converts automatically.
| Provider | Charge on the first slice | Where it falls away |
|---|---|---|
| Interactive Brokers, automatic conversion | 0.03% | Flat, no tiering published |
| interactive investor, Premium | 0.25% | Flat |
| Freetrade, Plus | 0.39% | Flat |
| Freetrade, Standard | 0.59% | Flat |
| AJ Bell | 0.75% | 0.50% on the next £10,000, 0.25% over £20,000 |
| interactive investor, Core | 0.75% | Flat |
| Freetrade, Basic | 0.99% | Flat |
| Hargreaves Lansdown | 0.99% | 0.50% to £25,000, 0.20% above |
That's a spread of 33 times between the top and the bottom of the published range. On a £10,000 purchase it's £99 against £3.
The percentage isn't the interesting part. What it's charged on is. An account fee is levied on your balance, every year, whether you do anything or not. A foreign exchange fee is levied on money crossing a currency boundary, once, at the moment it crosses. Convert £120,000 in one go at 0.99% and you've paid £1,188 and you're finished, however long you hold. Pay 0.15% a year on the same money for 20 years and you've paid 3% of it. The conversion charge reads worse and behaves better, right up to the point where you start converting every month.
The cost drag tracks your contributions, not your portfolio
Not everyone converts once. Plenty of people pay in monthly instead, and that changes the arithmetic completely, because a per-trade charge scales with what you put in rather than with what you've built up.
Take £500 a month for 20 years. That's £120,000 of contributions, Every one of those £500 conversions sits inside the first tier of the two tiered schedules above, and the flat rates apply throughout, so the headline rate is what you pay on all of it. At the 0.99% charged by Hargreaves Lansdown and by Freetrade's Basic plan, the 20-year bill is £1,188. At the 0.75% charged by AJ Bell and by interactive investor's Core plan, £900. At Freetrade Standard's 0.59%, £708. At Freetrade Plus's 0.39%, £468. At interactive investor Premium's 0.25%, £300. At the 0.03% Interactive Brokers adds on an automatic conversion, £36. The distance between the ends of that range is £1,152, on identical contributions into an identical portfolio.
The chart plots those six figures. What it doesn't show is any relationship to the size of the pot, and that absence is the point. A portfolio that has tripled over those two decades pays exactly the same foreign exchange fees as one that has halved, because the charge attaches to the £500 going in, not to the balance sitting there. That is the reverse of every percentage-of-assets charge you meet, and it's why this particular cost drag flattens as a portfolio matures while the other layers keep growing with it. The full stack is worth seeing together, and we've ranked the cost of investing in the UK layer by layer.
Splitting one conversion into 15 smaller ones costs £24.50 more
The tiering rewards size, and it resets on every single deal. Hargreaves Lansdown spells it out: "The FX charge is applied to each deal value band. For example, on a £15,000 deal, the charge will be 0.99% of the first £10,000 and 0.50% of the next £5,000." That comes to £124, a blended 0.83%. AJ Bell describes its own charge the same way, as "a blended rate based on the value of the deal that falls into each tier".
Now run the same £15,000 through as 15 separate £1,000 deals. Every pound sits in the top band, the rate is 0.99% throughout, and the bill is £148.50. Splitting cost £24.50 and reached no tier at all. That's the mechanism behind the monthly-contribution figures above. Drip-feeding is, among other things, a decision to pay the first-tier rate forever.
It also explains why the tiers look more generous than they behave. Hargreaves Lansdown's 0.20% band starts above £25,000, and AJ Bell's 0.25% band above £20,000. Those are large single conversions by retail standards, and nobody reaches them by accident.
Converting dividends to sterling is the charge that genuinely repeats
Buying isn't the only conversion. Income arriving in dollars has to become sterling, and platforms price that separately. Hargreaves Lansdown converts dividends and corporate action proceeds at the interbank rate, "to which we add an additional spread of 1% as our charge". AJ Bell lists a "foreign exchange charge payable when we have to convert any dividends or corporate action payments into sterling" of 0.50%.
This is the one that behaves like an ongoing charge, because it recurs whether you trade or not. It's also small. The S&P 500 index dividend yield was 1.13% on the State Street SPDR S&P 500 UCITS ETF factsheet dated 31 July 2026. A 1% spread on 1.13% of a portfolio is 0.0113% a year. That's worth saying plainly, because the repeating charge is the one people expect to compound into something, and at current US yields it doesn't.
A sterling-quoted fund converts on your behalf and never itemises it
Buy a sterling-quoted global fund rather than individual US shares and no platform foreign exchange fee appears on your contract note at all. The conversion still happens. It happens inside the fund, when the manager buys American, Japanese and European stock with money you handed over in pounds.
Vanguard's self-managed service costs document, dated 28 July 2026, defines transaction costs as "all costs and charges incurred as a result of the acquisition and disposal of underlying investments within the fund", and the list of what that includes runs "broker commissions, entry and exit charges, spreads, stamp duty, transactions tax, and foreign exchange costs". For the accumulating share class of the FTSE All-World UCITS ETF, those transaction costs were 0.03% as at 31 December 2025, against ongoing costs of 0.14%. The regulator uses the same taxonomy. The FCA's cost table, in force from 6 April 2026, lists "foreign exchange costs" among the transaction costs a firm has to aggregate and disclose.
What you can't do is pull the currency component back out. That 0.03% covers dealing, spreads, taxes and conversion in a single number, and no published breakdown separates them. So the honest claim here is a narrow one. Routing international exposure through a sterling-quoted fund moves the conversion from a line you can price to a line you can't, and the total it lands inside is smaller than most platform charges on a monthly purchase. It doesn't make the conversion free.
The strongest objection: foreign exchange fees are only the part you can see
Here's the case against making much of any of this. The charge you can measure isn't the charge that moves your money.
Every platform here quotes a percentage on top of a rate it sources elsewhere. Hargreaves Lansdown converts "at the prevailing interbank exchange rate, by a UK-based market maker". Interactive investor says that "when we convert your currency, we use the current exchange rate (or 'spot rate')", and then applies its charge. Neither prints the rate it actually used against a public benchmark on your contract note. So the published percentage is a spread over the interbank rate that you can read but can't audit, and it's a floor on the cost rather than a measurement of it. We've written separately on how those currency conversion costs are quoted.
The exchange rate itself is a much larger number than any of these fees. Hargreaves Lansdown's own page puts it flatly: "Fluctuations in the exchange rate will affect the sterling value of your overseas holdings." Whether you want that exposure is a different question from what conversion costs, and currency hedging is the usual answer to it. Hedging isn't free either. Vanguard's USD Corporate Bond UCITS ETF carries ongoing costs of 0.07% in its unhedged accumulating share class and 0.10% in the sterling-hedged one, a difference of 0.03 percentage points a year. That difference is annual, so unlike a conversion charge it compounds.
A low foreign exchange rate also rarely turns up on its own. Interactive Brokers' 0.03% belongs to a broker whose pricing page notes that "a minimum activity fee applies to ISA/JISA accounts", and whose stand-alone spot currency orders carry a minimum commission of USD 2.00 per order at the first tier. On a USD 5,000 conversion that minimum by itself is 0.04%. Freetrade's 0.39% arrives with a £9.99 monthly subscription, and interactive investor's 0.25% with one at £39.99. The FX line is one column of a bill, and platform fees settle the rest of it.
What these rate cards can't tell you
Three limits, stated plainly.
They're prices, not measurements. A published schedule says what a firm charges, not what a sample of executed conversions cost. The FCA requires firms to show "the total sum of aggregated costs" as a cash amount and as a percentage, and to illustrate the cumulative effect of costs on the return, but those arrive on your own statement rather than in any table an outsider can compare.
They move. AJ Bell's schedule is dated in force from 1 May 2026. The Hargreaves Lansdown page carries no effective date at all, and neither does interactive investor's. Every figure here is a figure read on 19 August 2026, and the only safe assumption is that some of them have changed since.
And the 20-year arithmetic is deliberately simple. It applies a flat first-tier rate to £120,000 of contributions and stops. It doesn't compound what you'd otherwise have kept, it assumes the plan and the rate card never change, and it takes no view on returns. Those choices forecast nothing. They isolate one charge so its shape is visible.
What would change this
If a platform began charging for currency exposure on the balance rather than on the transaction, the whole comparison inverts. A per-trade charge is bounded by what you contribute. A per-year charge is bounded by nothing. Nobody in this sample does that today.
If contract notes carried the interbank rate used alongside the rate you got, the published percentage would stop being the only measurable number, and it would become possible to test whether 0.99% is really 0.99%. The FCA's rules require aggregation and a cumulative-effect illustration. They don't require that comparison on the trade itself.
And if dividend yields rose materially, the one conversion charge that genuinely repeats would stop rounding to nothing. At 1.13% it's noise. At three times that, it isn't. The rate cards would be unchanged. What would change is which line on them is worth reading first.