Foreign exchange is one area where many travellers lose significant amounts of money through avoidable fees and poor rate decisions. Understanding how exchange rates work, where to find the best rates, and which products to avoid can save hundreds of pounds on a single holiday. This guide cuts through the confusion with practical, actionable advice.
How Exchange Rates Work
An exchange rate is the price of one currency in terms of another. When you see GBP/EUR = 1.17, it means £1 buys €1.17. Exchange rates fluctuate constantly — driven by interest rate differentials, inflation, economic data, political events, and market sentiment.
The "interbank rate" (also called the mid-market rate) is the actual exchange rate used by banks when trading with each other. It's the fairest rate available. Bureaux de change, banks, and card companies all apply a margin on top of this rate — that's how they profit from currency exchange.
Calculating Currency Conversions
Foreign amount = Home amount × Exchange rate
Home amount = Foreign amount ÷ Exchange rate
If £1 = €1.17 and you want to convert £500 to Euros:
€ amount = 500 × 1.17 = €585
If you receive €300 and want to know its sterling value:
£ amount = 300 ÷ 1.17 = £256.41
But in practice, you never get the interbank rate. A bureau charging a 3% margin gives you a rate of 1.17 × 0.97 = 1.135. For £500: €567.50 instead of €585 — you lose €17.50 on the exchange.
Comparing Currency Exchange Options
| Method | Typical Margin | Cost on £500 | Verdict |
|---|---|---|---|
| Airport bureau de change | 5–10% | £25–£50 lost | Worst option — avoid |
| High street bank | 3–5% | £15–£25 lost | Poor — better options available |
| Online pre-order (Post Office, M&S, etc.) | 1.5–3% | £7.50–£15 lost | Decent for cash |
| Travel money specialist (Wise, Revolut) | 0.3–0.7% | £1.50–£3.50 lost | Best for card use |
| Wise debit card | 0.3–0.7% | £1.50–£3.50 lost | Best option for most travellers |
| Revolut | 0% (standard hours) | £0 (up to limit) | Excellent, with caveats |
| Standard debit card abroad | 2.75–3.5% | £14–£17.50 lost | Avoid unless abroad charge-free |
Travel Money Cards vs Regular Debit Cards
Specialist travel cards (Wise, Revolut, Starling)
These offer rates close to the interbank rate with low fees:
- Wise: Uses the mid-market rate with a small conversion fee (0.35–1.5% depending on currency). No subscription required. Transparent fees displayed upfront.
- Revolut: Offers interbank rates for free on standard plan up to a monthly limit, then a 0.5% fee. Weekend rates are marked up 0.5–1%.
- Starling Bank: Uses Mastercard's rate with 0% foreign transaction fee. Excellent for debit card use abroad — no ATM fees within Europe.
Dynamic Currency Conversion (DCC) — Always Decline
When a foreign card terminal or ATM asks "Do you want to pay in your home currency (£)?" — always choose the local currency. DCC lets the merchant apply their own exchange rate, which is typically 3–7% worse than your card's rate. This is one of the most common ways travellers get quietly stung.
ATM Withdrawal Strategy
ATMs abroad are fine if you use the right card. Avoid ATMs run by independent operators (Euronet, Moneybox) which charge fixed fees of €3–€5 per withdrawal regardless of amount. Use bank ATMs and withdraw larger amounts less frequently to minimise per-transaction fees. On Revolut, you get 5 free withdrawals per month up to £200 on the standard plan; further withdrawals incur a fee.
The Commission-Free Trap
"No commission!" is a marketing claim, not a guarantee of a good rate. A bureau can be commission-free but apply a 7% exchange rate margin — far worse than a competitor charging a flat £4 fee. Always compare the actual rate offered against the mid-market rate (check Google or xe.com), not just the headline fee structure.
budget">Planning Your Currency Budget
For a 7-day holiday in Europe spending €1,200:
- Using airport bureau at 7% margin: you need £1,075 to get €1,200 (effective rate ~1.116)
- Using Wise at 0.5% margin: you need £1,033 to get €1,200 (effective rate ~1.161)
- Saving: £42 on a single holiday
Scale this over a family of four taking two holidays a year and specialist cards save £160–£200 annually.
Summary
The interbank (mid-market) rate is your benchmark — compare any offered rate against it. Airport bureaux de change offer the worst rates; specialist travel cards (Wise, Revolut, Starling) offer the best. Always decline dynamic currency conversion at terminals and ATMs. For cash, pre-order online rather than buying at the airport. Our currency converter shows the real mid-market rate so you can evaluate any offer you receive.