Understanding Currency Swaps: Definition, Benefits, and Risks

Search Fintrev

Search our guides, reviews and glossary.

A currency swap is a contract in which two parties exchange principal and interest payments denominated in two different currencies over an agreed term. Typically they swap principal amounts at the start, pay each other interest in the currency each one received, and then return the original principal amounts at maturity at the same exchange rate used on day one. The result is that each side converts a loan or asset in one currency into an equivalent position in another without borrowing directly in the foreign market.

What Is a Currency Swap?

A currency swap is an over-the-counter derivative: a privately negotiated contract whose value depends on exchange rates and interest rates. Unlike a spot currency trade, which settles once, a swap creates a schedule of cash flows that can run for years.

Each party has a leg in the swap. One leg is denominated in, say, US dollars and the other in euros. Each leg has its own notional principal, interest rate (fixed or floating), payment dates and day-count convention. The two notional amounts are linked by an exchange rate agreed at inception, usually the spot rate on the trade date.

Terminology is not perfectly consistent. In strict textbook usage, a “currency swap” has two fixed legs, and a swap where one or both legs float is a “cross-currency swap” (a cross-currency basis swap when both legs float). In everyday market and corporate usage, “currency swap” covers all of these. The mechanics below apply to every variant; only the interest calculation changes.

How Currency Swaps Work

A standard currency swap agreement has three stages.

1. Initial exchange of principal. On the start date, Party A pays Party B an amount in currency X, and Party B pays Party A the equivalent amount in currency Y. The ratio between the two amounts is the swap’s exchange rate. Swapping €10 million for $11 million, for example, implies a EUR/USD rate of 1.10.
2. Periodic interest payments. During the term, each party pays interest to the other in the currency it received. The party holding the euros pays euro interest, and the party holding the dollars pays dollar interest.
3. Final re-exchange of principal. At maturity, the parties hand back the original principal amounts: the same €10 million and $11 million, regardless of where EUR/USD trades that day.

The initial exchange is optional. Some swaps skip it, particularly when a company already holds the foreign currency or only wants to convert the interest cost of an existing loan. In that case the notional amounts still determine the interest payments, and the final exchange may or may not take place depending on the contract.

Why the exchange rate is fixed for the whole term

The fixed rate at both ends is what makes a currency swap a hedge. A company that borrows dollars, swaps them into euros, and invests in a European project knows from day one exactly how many euros it must return to get back the dollars it needs to repay its lenders. If the euro weakens during the term, the company still receives the full dollar principal at maturity.

The trade-off is that both parties give up any gain from a favorable rate move on the principal. If the euro strengthens, the party that agreed to return euros at 1.10 would have been better off converting at the market rate. In value terms, one side’s gain on the principal exchange is always the other side’s loss.

How the interest rates are set

Each leg’s rate is built from a benchmark and a spread:

• Benchmark. Floating dollar legs are now generally referenced to SOFR, the Secured Overnight Financing Rate, which is based on overnight Treasury repo borrowing and replaced US dollar LIBOR. Other currencies use their own overnight benchmarks, such as €STR for euros or SONIA for sterling. A fixed leg is priced off the swap curve for that currency and maturity.
• Spread. The rate is adjusted by a number of basis points (one basis point is 0.01%) reflecting market conditions on the trade date, the parties’ creditworthiness and the dealer’s costs.
• Cross-currency basis. In cross-currency basis swaps, one floating leg carries an extra spread, the basis, reflecting supply and demand for funding in one currency against the other. A non-zero basis means borrowing a currency through swaps costs more or less than the two benchmark rates alone suggest.

Worked Example: A Fixed-for-Fixed Currency Swap

The following example is hypothetical, with rates and amounts chosen to keep the arithmetic simple.

A US manufacturer is building a plant in Germany and needs €50 million for five years. It can borrow dollars cheaply at home, but as a foreign borrower it would pay more in the euro bond market. A German company in the reverse position needs $55 million for a US expansion. With EUR/USD at 1.10, the two arrange (usually through a bank acting as intermediary) a five-year fixed-for-fixed swap:

• US company pays $55 million and receives €50 million at the start.
• US company pays 3.0% fixed annually on €50 million.
• German company pays 4.5% fixed annually on $55 million.
• At maturity the principal amounts are re-exchanged at 1.10.

The US company uses the $2,475,000 it receives each year to pay interest on its own dollar loan (assuming that loan also costs 4.5%). Its net cost is the €1,500,000 per year it owes under the swap, which it can pay from the euro revenue the German plant generates. In effect, it has turned a dollar loan into a euro loan at a fixed euro rate.

Now assume EUR/USD trades at 1.25 at maturity. Buying €50 million in the market would cost $62.5 million, but the swap requires the US company to hand over only the €50 million it already holds (from the plant’s euro earnings or a refinanced euro facility) in exchange for exactly $55 million. Its dollar liability is covered at the original rate. The German company, which needed euros for its own euro obligations, is likewise unaffected by the move.

Netting the payments

Because the two interest payments are in different currencies, they are normally paid gross: each side makes its own payment on the due date. Some contracts convert the payments into one currency at the prevailing rate and net them, so only the party owing more pays the difference. If, in year three, EUR/USD were 1.20, the €1.5 million would be worth $1.8 million, and the German company would pay the US company $675,000 ($2,475,000 minus $1,800,000). Netting reduces the money moving between the parties but brings exchange rate exposure into each settlement amount.

Interest Rate Combinations

The interest legs can be structured in three ways:

• Fixed for fixed: both parties pay fixed rates, as in the example above. This is the classic currency swap. It converts the currency of a liability while keeping its cost fixed.
• Fixed for floating: one party pays a fixed rate in one currency, the other a floating rate in the other, converting both currency and rate type at once. A company with a fixed-rate euro bond could swap into floating-rate dollar debt, for instance.
• Floating for floating: both legs float off their respective benchmarks, with a basis spread on one leg. This cross-currency basis swap, used heavily by banks for funding, mainly moves the currency and leaves interest rate exposure floating on both sides.

Payment frequency is negotiated. Quarterly or semiannual payment schedules are common, and the calculation period and payment date do not have to coincide.

Valuing a Currency Swap After Inception

At the start, a swap priced at market rates has a value close to zero for both parties. After that, its value changes as interest rates and the exchange rate move. A common way to value it is to treat each leg as a bond:

Value to the party receiving dollars and paying euros = PV(dollar leg) − S × PV(euro leg)

where PV(dollar leg) is the present value of all remaining dollar payments, including the final principal, discounted on the dollar curve. PV(euro leg) is the same for the euro payments, discounted on the euro curve, and S is the current spot rate in dollars per euro.

Using the earlier example, suppose that right after inception S rises from 1.10 to 1.25, with interest rates unchanged. The euro leg the US company owes is now worth more in dollars, so the swap’s value becomes negative to the US company and positive to the German company. That mark-to-market figure is roughly what each side would pay or receive to terminate early, and it is the amount at risk if the counterparty defaults. Real valuations also account for the cross-currency basis and collateral terms, which makes less liquid currency pairs harder to value accurately.

Why Companies and Central Banks Use Currency Swaps

Matching debt to income (cash flow matching). A company with revenue in one currency and debt in another faces a mismatch: every rate move changes the real cost of servicing the debt. Swapping the debt into the revenue currency aligns outflows with inflows. This is the most direct corporate reason to enter a currency swap.

Lower borrowing costs and access to foreign capital. Borrowers tend to get better terms in their home markets, where lenders know them. Two companies can each borrow where they are strongest and swap the proceeds, so each ends up with the currency it needs at a rate that may beat borrowing directly abroad. A company that cannot easily issue debt in a foreign market gains economic exposure to that funding market without entering it.

Hedging long-term investments. Foreign subsidiaries, project finance and long-dated bond portfolios are exposed to exchange rates over years, beyond the horizon where short-dated hedges are convenient. A swap covers the whole period with a single contract.

Asset-liability management at financial institutions. Banks and insurers hold assets and liabilities in many currencies. Cross-currency swaps let them align the currency of what they own with the currency of what they owe.

Central bank swap lines. Central banks sign currency swap agreements with each other so that one can lend the other’s currency to its domestic banks during funding stress. The Federal Reserve’s dollar liquidity swap lines with other major central banks, used heavily during the 2008 financial crisis and again in 2020, are the best-known case. The mechanics match a corporate swap: currencies are exchanged and returned later at the same rate, with interest paid on the borrowed side.

Steps to Execute a Currency Swap

Beyond the three stages above, most corporate currency swaps involve:

1. Documentation. The parties, or the company and its bank, usually sign an ISDA Master Agreement, the standard framework for over-the-counter derivatives. A Credit Support Annex can be added to govern collateral.
2. Negotiating terms. They agree on the currencies, notional amounts, exchange rate, term, interest rate on each leg, payment frequency, and whether principal is exchanged at the start, at the end, or both.
3. Interim adjustments. Some structures include amortizing principal or periodic notional resets (in mark-to-market cross-currency swaps) to limit the build-up of exposure from exchange rate moves.
4. Early exit. Contracts may include early termination rights or restructuring clauses. A swap exited early is closed at its mark-to-market value.

Risks of Currency Swaps

Swaps redistribute risk; they do not eliminate it. Each party trades one exposure for a set of others.

Counterparty risk

Each side depends on the other making payments for years. If a counterparty defaults when the swap has positive value to you, you lose that value and must replace the hedge at current market rates. Because currency swaps include a large final principal exchange, counterparty exposure can grow considerably over the term. It is managed by dealing with creditworthy institutions, posting collateral under a Credit Support Annex, and, for some products, clearing through a central counterparty.

Exchange rate risk

The swap fixes the rate on the principal amounts but protects nothing outside the contract. Netted settlements move with the exchange rate. If the underlying business cash flows fall short of forecast, for instance if a foreign subsidiary earns less than expected, the company can end up over-hedged, holding a currency liability it no longer needs.

Interest rate risk

A floating leg changes with its benchmark, so the party paying it faces higher payments when rates rise. Even fixed legs carry interest rate risk in value terms: the swap’s mark-to-market moves as the yield curves in both currencies shift, which matters for collateral calls and accounting.

Liquidity risk

Currency swaps are bespoke contracts. Exiting before maturity requires either negotiating a termination with the counterparty or entering an offsetting swap, and for long tenors or less traded currency pairs the cost of doing so can be high.

Valuation and operational risk

Valuing a swap requires yield curves for both currencies, the spot rate, and the cross-currency basis. For thinly traded currencies or complex structures these inputs are hard to observe, which can lead to inaccurate financial reporting, disputes over collateral, and mistakes in hedge accounting.

Why Swapping Currency Costs Money

A currency swap is not free even when the headline rates look fair. The costs come from several sources: the dealer’s bid-ask spread built into each leg’s rate, a credit charge for counterparty risk, the cost of posting collateral, and the cross-currency basis, which can make one currency more expensive to obtain through swaps than interest rate differentials alone would imply. Early termination adds the mark-to-market settlement plus the dealer’s spread on the unwind.

Currency Swaps vs. Similar Contracts

FX swaps. An FX swap is a spot trade paired with an opposite forward trade. Two currencies are exchanged now and swapped back later at a different rate, the gap reflecting the interest differential. There are no separate interest payments and the tenor is usually short, which makes FX swaps a tool for short-term liquidity management and rolling positions. A currency swap pays interest explicitly and runs for years.

Interest rate swaps. An interest rate swap exchanges fixed for floating interest (or one floating rate for another) in a single currency. The notional principal is only used to calculate payments and never changes hands. A currency swap adds a second currency and, usually, a real principal exchange, so it handles exchange rate and interest rate exposure together.

Forwards and futures. A currency forward or futures contract locks in an exchange rate for one transaction on one future date. A swap creates a series of payments over time. Forwards suit known one-off amounts, such as an import invoice due in three months. Swaps suit ongoing exposures such as debt service or a multi-year investment. A currency swap can be viewed as a bundle of forward exchanges, one per payment date, packaged into a single contract.

Options. A currency option gives the right, not the obligation, to exchange at a set rate, in return for a premium. A swap is a binding obligation for both sides with no upfront premium when priced at market.

Where Currency Swaps Came From

Currency swaps grew out of the parallel and back-to-back loans of the 1970s, which companies in two countries used to get around exchange controls, the legal restrictions on buying or moving foreign currency, such as those then in force in the UK. Those loans required two separate agreements, and a default on one did not release the other. The swap combined both legs into a single contract. The landmark deal was the 1981 swap in which the World Bank exchanged dollars it raised for IBM’s Swiss franc and Deutsche mark obligations, gaining those currencies at better rates than direct borrowing. As exchange controls were removed, swaps shifted to hedging long-term exposures and lowering funding costs.

FAQs

The Bottom Line

Currency swaps matter most to companies with debt in one currency and revenue in another, and to banks, insurers and central banks managing funding across currencies. A swap can lock in a long-term exchange rate and may lower borrowing costs, but it trades currency risk for counterparty, liquidity and valuation risks. Dealer spreads, collateral and the cross-currency basis add cost, so the hedge works best when it matches real, forecastable cash flows.