Currency Exchange: The Real Cost of FX Fees and Spread
When you exchange currency, you rarely see the full cost. The headline exchange rate shown by banks includes a markup above the interbank (mid-market) rate. Add fixed transaction fees and the actual cost can reach 3–5% of the transfer value — far more than advertised "no fee" services imply.
How the Hidden Cost Works
True FX Cost = (Spread × Transfer Amount) + Fixed Fees Spread = (Mid-market rate − Provider rate) ÷ Mid-market rate × 100 Example: Mid-market rate £1 = €1.1850 Bank rate offered: £1 = €1.1500 Spread: (1.1850 − 1.1500) ÷ 1.1850 × 100 = 2.95% On £10,000 transfer: Hidden cost = £295 + any fixed fees
Provider Comparison (Illustrative, not real-time)
| Provider Type | Typical Spread | Fixed Fee | Cost on £10,000 |
|---|---|---|---|
| High street bank | 2.5–4% | £0–£25 | £250–£425 |
| Post Office / travel money | 2–3.5% | £0 | £200–£350 |
| Specialist FX broker | 0.3–1% | £0–£10 | £30–£110 |
| Multi-currency card (Wise etc.) | 0.4–0.7% | Small | £40–£75 |
| Crypto exchange | 0.5–2% + volatility | Variable | Variable |
Rates are illustrative. Always compare live rates before transferring.
What-If Scenarios
Scenario 1: Annual overseas property maintenance
Regular transfers of £2,000/month (£24,000/year) to eurozone property costs
| Provider | Spread | Annual Cost |
|---|---|---|
| Bank (3%) | 3% | £720 |
| Specialist broker (0.5%) | 0.5% | £120 |
| Saving | £600/year |
Scenario 2: One-off large transfer (buying property abroad)
£200,000 transfer. Bank at 2.5% spread = £5,000 hidden cost. Specialist at 0.4% = £800. Saving: £4,200.
Scenario 3: Holiday money — when spread matters less
£1,000 holiday money. At 3% spread vs 0.5%: difference = £25. For small amounts, convenience may outweigh the saving. The calculation matters most for large or regular transfers.
Frequently Asked Questions
→ Model regular overseas costs with the Savings Growth Calculator
Indicative only. FX rates change by the second. Always get live quotes from multiple providers before transferring. This guide does not recommend specific providers.