Whether you’re paying a European supplier, receiving payment from a US client, or moving funds ahead of a property purchase abroad, currency exchange sits at the heart of almost every international business transaction. Yet most business owners have only a vague understanding of how it actually works — and that knowledge gap can be surprisingly costly.
This guide explains how currency exchange works in plain terms, covers the key payment systems businesses use (including SEPA and SWIFT), defines the core concepts you’ll encounter, and shows you how to make smarter decisions when converting foreign currency. See also how exchange rates affect UK business profits and where the risk typically sits.
What Is Currency Exchange? (International Money Transfer Definition)
At its most basic, currency exchange is the process of converting one currency into another at an agreed rate. The international money transfer definition is similarly straightforward: the electronic movement of funds from one country to another, typically involving a currency conversion along the way.
In practice, these transactions involve several layers of infrastructure — payment networks, correspondent banks, foreign exchange markets, and regulatory systems — that determine how fast your money moves, how much it costs, and what rate you get.
Understanding each layer helps you make better decisions as a business.
The Foreign Exchange Market
Currency exchange rates aren’t set by any single bank or government — they’re determined by the global foreign exchange (FX) market, which is the largest and most liquid financial market in the world. Daily trading volumes exceed $7 trillion, with participants ranging from central banks and institutional investors to commercial banks and currency brokers.
The rate you see on Google when you search “GBP to USD” is the mid-market rate — the midpoint between the buy and sell prices in the wholesale interbank market. This is the “real” rate, and it’s the benchmark against which all other rates should be measured.
When a bank or transfer provider quotes you an exchange rate, they add a margin on top of the mid-market rate — this is how they make money on the conversion. The margin varies enormously between providers. Find out exactly why banks give worse exchange rates and how much that costs in real terms.
- High street banks: typically 2–4% above mid-market
- Online transfer platforms (Wise, OFX): typically 0.3–1.5%
- Currency brokers (Cambridge Currencies): typically the most competitive rates available, particularly for larger amounts
On a £50,000 business transfer, the difference between a 3% bank margin and a 0.5% broker margin is £1,250. That’s a significant sum — and it recurs every time you convert.
How Does Currency Exchange Actually Work?
When your business initiates an international payment, here’s what happens behind the scenes:
Step 1: You instruct your provider. You tell your bank, transfer platform, or currency broker how much you want to send, in which currency, and to which recipient. You’re quoted an exchange rate and a fee.
Step 2: Your funds are debited. The amount in your home currency (plus any fees) is taken from your account.
Step 3: The currency conversion occurs. Your provider converts your home currency into the destination currency, either from their own FX position or via the wholesale interbank market. The rate applied is the one you were quoted, plus their margin.
Step 4: The funds are transmitted. The converted funds are sent to the recipient via the relevant payment network — SWIFT, SEPA, or another local payment rail depending on the destination. Our SWIFT transfers guide explains this in detail.
Step 5: The recipient receives the funds. Depending on the network used and any intermediary banks involved, the recipient receives the funds within minutes to several business days. See our guide on how long international bank transfers take for exact timelines by payment type.
SEPA: Cross-Border Payments Within Europe
SEPA stands for the Single Euro Payments Area. It’s a payment integration initiative that allows businesses and individuals in participating countries to make euro-denominated transfers as easily and cheaply as domestic payments.
SEPA currently covers 36 countries, including all EU member states plus the UK, Switzerland, Norway, Iceland, and several others. Despite Brexit, the UK remains a SEPA participant — meaning UK businesses can still send and receive euro payments via SEPA.
Types of SEPA payment:
SEPA Credit Transfer (SCT) is the standard transfer, used for one-off or recurring euro payments. Processing time is typically one business day, and costs are minimal.
SEPA Instant Credit Transfer (SCT Inst) is the real-time version, settling within 10 seconds, 24/7/365, up to a maximum of €100,000 per transaction.
SEPA Direct Debit (SDD) allows businesses to collect recurring payments from customers’ euro accounts — the European equivalent of a direct debit.
SEPA does not handle currency conversion — it is a euro-only system. If you’re sending GBP to a European supplier who invoices in EUR, the GBP-to-EUR conversion happens before the SEPA transfer is initiated. See our guide to the best way to transfer pounds to euros for the most cost-effective approach.
SWIFT: International Payments Beyond Europe
SWIFT stands for the Society for Worldwide Interbank Financial Telecommunication. It is a secure messaging system that allows financial institutions to communicate payment instructions to each other. SWIFT connects over 11,000 financial institutions in more than 200 countries.
When you send a SWIFT payment, your bank sends a standardised message to the recipient’s bank — either directly or via one or more correspondent banks in between. Each correspondent bank relays the message and processes the transfer through its own accounts.
This correspondent banking chain is why international SWIFT transfers can take 1–5 business days, and why bank wire transfer fees can be deducted at each stage — meaning the recipient sometimes receives slightly less than the amount sent.
SEPA vs SWIFT: Which Should Your Business Use?
The choice between SEPA and SWIFT for cross-border payments depends on the destination and the currency.
Use SEPA when: you’re sending or receiving euros within the SEPA zone, and speed and low cost are priorities.
Use SWIFT when: you’re sending to a country outside the SEPA zone, in a currency other than euros, or making a large one-off payment requiring a full audit trail.
For most UK businesses with European operations, the workflow looks like this: convert GBP to EUR via a currency broker like Cambridge Currencies at a competitive rate, then send the euros via SEPA Credit Transfer. This combines the best exchange rate with the cheapest, fastest euro delivery method. See our guide to the best way to pay overseas suppliers from the UK for the full breakdown.
Exchange Rate Types Your Business Will Encounter
Spot rate. The current market rate for immediate exchange. Settlement typically occurs within two business days.
Forward rate. A rate agreed today for a currency exchange that will happen at a specified future date. Businesses use forward contracts to lock in a rate months in advance, eliminating uncertainty about what they’ll pay or receive in their home currency. Essential for businesses with predictable future foreign currency flows. See our full forward contract guide for worked examples.
Market order / limit order. An instruction to convert currency automatically when the market reaches a rate you specify. Our limit orders guide explains exactly how these work.
Indicative rate vs. live rate. Many providers show an indicative rate on their website — a general guide — but the rate applied to your actual transfer is the live rate at the moment of execution. With Cambridge Currencies, you agree a live rate with your account manager before the transaction is processed.
How Exchange Rates Are Quoted
Exchange rates are quoted as a currency pair — for example, GBP/USD 1.2750. This means one British pound buys 1.2750 US dollars at that moment. You can check live rates with our currency converter.
Even relatively small rate movements matter at scale. A 2% move in GBP/EUR on a €200,000 annual supplier bill is a £3,200 swing in your costs. Understanding this is why FX risk management — not just currency conversion — is important for any business with meaningful international exposure. Our guide to currency hedging for UK small businesses covers the practical options.
What Affects Exchange Rates?
Exchange rates fluctuate constantly, driven by a complex mix of economic and political factors. The main drivers include interest rates, inflation, economic data releases, political events, and market sentiment. See our currency forecasts hub for current analysis of the key pairs affecting UK businesses, and our Bank of England rate decision tracker for the latest on UK monetary policy.
For most businesses, trying to predict these movements is neither practical nor productive. The more useful approach is to put a simple FX risk management strategy in place — using forward contracts for known future exposures — rather than speculating on rate direction.
Practical Tips for Businesses Converting Currency
- Never use your high street bank for regular FX conversions. The rate margins are consistently the worst available. For any conversion above £1,000, a specialist is almost always cheaper. See our guide on who gives the best exchange rates for large transfers.
- Compare on total cost, not just the fee. A provider with no transfer fee but a 3% exchange rate margin is far more expensive than one charging a small fee with a 0.5% margin on larger amounts.
- Build an FX strategy, not just ad hoc conversions. If your business has predictable foreign currency flows, work with a currency specialist to put a hedging strategy in place.
- Use multi-currency accounts to hold foreign currency. Rather than converting immediately on receipt, hold foreign currency in a dedicated account and convert when the rate is favourable.
- Keep records of every FX transaction. Exchange rate gains and losses are taxable events in most jurisdictions.
Why Cambridge Currencies for Business FX?
Cambridge Currencies combines competitive exchange rates with personalised service that makes a real difference for businesses managing complex or high-value currency needs. Every business client is assigned a dedicated account manager who learns your payment patterns, helps you navigate compliance requirements, and can execute transactions quickly when timing matters. All funds are processed through FCA-authorised payment partners and are fully safeguarded.
Summary
Currency exchange is the conversion of one currency into another at a rate determined by the global FX market. International money transfers use payment networks — primarily SEPA for euro payments within Europe, and SWIFT for payments worldwide — to move funds between banks across borders. The rate you’re offered is the mid-market rate plus a margin, and that margin varies enormously between providers. Understanding how the system works — and choosing the right provider for your specific needs — can save your business thousands per year. Speak to a Cambridge Currencies specialist or request a free quote to get started.
This article is for informational purposes only and does not constitute financial guidance. Always consult a regulated specialist for guidance specific to your business circumstances.
