Interest-rate swaps: fix floating business debt without replacing the loan

An interest-rate swap can convert the economic cost of floating-rate debt into a fixed-rate exposure without changing the underlying loan. The company continues paying the lender under the loan and separately exchanges fixed and floating interest amounts with the swap counterparty.

The swap exchanges fixed and floating interest cash flows

In a common pay-fixed swap, the company pays a fixed swap rate and receives a floating amount linked to SONIA. The floating receipt offsets much of the benchmark component on the underlying loan, leaving the borrower economically closer to fixed-rate debt plus its loan margin.

Principal is generally a notional amount used to calculate interest rather than cash exchanged under a standard interest-rate swap.

Match notional and maturity to the underlying debt

If the loan amortises from £10 million to £5 million over three years, a flat £10 million swap can become over-hedged. Build the hedge notional around expected principal.

A five-year swap against debt expected to refinance in two years can also create a standalone derivative after the loan disappears. Maturity should match commercial reality, not simply the maximum offered term.

Fixed certainty can create mark-to-market value and closeout cost

If market rates fall after the company fixes, the swap can have negative value because the company remains committed to the higher fixed rate. Closing the swap early can therefore require a payment.

If rates rise, the swap can gain value economically. The purpose is to stabilise interest cost, not to win a market trade with hindsight.

Derivative documentation creates counterparty considerations

Material swaps can sit under ISDA or bank derivative documentation. Depending on the parties and terms, collateral, credit limits or cross-default arrangements can apply.

Review what happens if the loan defaults or is refinanced. A swap with the same bank can still be a separate legal contract with its own termination calculation.

Hedge accounting needs deliberate documentation

HMRC's corporate-finance manuals treat swaps and other derivatives under the derivative-contract rules, while accounting standards can allow hedge accounting where the requirements are met.

Keep hedge designation, risk objective, notional and effectiveness evidence with the swap confirmation. Leaving derivative accounting until year end creates unnecessary audit and earnings volatility risk.

Use treasury limits rather than ad hoc hedging

Swaps are risk-management instruments but can create speculation if notional exceeds genuine debt exposure. Define permitted counterparties, maximum hedged percentage and maturity limits.

Report fixed, floating and hedged debt separately so the board can see the true interest-rate exposure after derivatives.

Worked example: a company has a £20 million SONIA-linked loan and swaps £12 million to fixed for three years. The remaining £8 million stays floating, giving the business a blended exposure rather than an all-or-nothing choice. If the loan later falls to £10 million, treasury needs to review whether the £12 million swap has become too large.

Ask for indicative closeout values periodically even when no early repayment is planned. Understanding the derivative's market value prevents management being surprised during a refinancing or sale when the swap must be terminated.

Keep swap cash flows distinct from loan interest in the ledger. The loan bank debit and swap settlement together create the hedged economics; combining them into one generic interest line can make it difficult to assess whether the hedge is performing as intended.

Use independent valuation for material swaps rather than relying only on the dealing bank. A second valuation source or treasury adviser can help the board understand closeout exposure during refinancing and reduce surprises when market value becomes significant.

Watch accounting volatility where hedge-accounting requirements are not met. The economic hedge can still protect cash while fair-value movements affect reported profit. Directors should distinguish cash-risk management from financial-statement presentation.

Plan for partial prepayment. If the company expects asset sales to reduce debt, consider a stepped swap notional or hedge only a core debt amount that is likely to remain. Flexibility at the start can avoid paying to unwind excess hedges later.

Check cash-settlement dates against loan interest dates. A swap may settle on a slightly different business-day convention from the underlying loan, creating temporary cash differences. Treasury should forecast both legs even when the economic hedge is well matched.

Use a hedge register that identifies the exact loan or debt tranche each swap supports. If a business has several floating facilities, a generic statement that "£10 million is swapped" is insufficient during refinancing or covenant review. The relationship between debt and derivative should be explicit.

Review hedge counterparties during lender changes. A company can refinance its loan away from Bank A while leaving the swap with Bank A, which can change collateral, documentation or relationship economics. Include derivative novation or termination in the refinancing workstream from the beginning.