Under FRS 102, a convertible instrument that lets the holder swap a fixed amount of debt for a fixed number of the issuer’s shares is a compound instrument: at issuance you split the proceeds between a financial liability, measured at the present value of the contractual cash flows discounted at the market rate for equivalent non-convertible debt, and an equity reserve holding the residual. That equity piece is never remeasured. The liability then accretes back to face value through the effective interest method, so reported interest expense runs higher than the cash coupon for the life of the instrument.
The rest of this article walks through the mechanics: when the split applies, how to calculate each side, what to do with transaction costs, how the liability behaves after day one, and what happens on conversion or redemption. If your entity applies adopted IFRS, FRS 101, or FRS 105 instead of FRS 102, the rules below don’t govern you; IAS 32 and IFRS 9 cover the equivalent ground for IFRS reporters.
When Split Accounting Applies: The Fixed-For-Fixed Test
Not every convertible qualifies for split accounting. The conversion feature only counts as equity if the holder can convert into a fixed number of the issuer’s own equity shares for a fixed amount of debt surrendered.1Croner Navigate. Accounting for Financial Liabilities and Equity Under FRS 102 A note stating “each £500 instrument converts into 10 ordinary shares” passes cleanly.
The test fails if either side floats. Variable conversion ratios tied to the share price at conversion, anti-dilution ratchets, reset features linked to future funding rounds, or a cash amount that moves with market conditions all break the fixed-for-fixed condition. When that happens, there is no equity component. The whole instrument is a financial liability, typically measured at fair value through profit or loss under Section 12. Every period, the fair value movement lands in earnings.
Because classification is set at inception and drives everything that follows, read the conversion clause carefully before assuming split accounting is available. Instruments that look like plain convertibles often contain features that quietly disqualify them.
Splitting the Proceeds at Issuance
Section 22.13 requires the issuer to allocate total proceeds between the liability and equity components using the residual method: value the debt first, and whatever is left is equity.1Croner Navigate. Accounting for Financial Liabilities and Equity Under FRS 102
Value the Liability
The liability equals the present value of every cash flow the issuer is contractually obliged to pay: each periodic coupon and the principal at maturity. Discount those cash flows at the rate the issuer would have to offer on a plain vanilla loan of the same amount, term, and credit quality. That market rate is almost always higher than the coupon on the convertible itself, because the holder accepts a lower coupon in exchange for the conversion option.
Calculate the Equity Residual
Equity component = total proceeds − liability fair value. That residual reflects what the holder effectively paid for the conversion option.
Worked Example
ABC Limited issues 1,000 convertible loan notes at par. Face value £500 each, total proceeds £500,000. Coupon 5% annual, paid in arrears. Maturity three years. Each note converts into 10 ordinary shares on maturity. A comparable three-year loan with no conversion feature would carry 8%.2ICAEW. Convertible Loan Notes
Discounting at 8%:
- Present value of principal: £500,000 ÷ (1.08)³ = £396,916
- Present value of coupons: (£25,000 ÷ 0.08) × (1 − 1/1.08³) = £64,427
- Liability component: £461,343
Equity residual: £500,000 − £461,343 = £38,657.
Day one entry: debit cash £500,000, credit financial liability £461,343, credit Conversion Option Reserve (or similarly named equity reserve) £38,657.2ICAEW. Convertible Loan Notes
Once made, this allocation is permanent. Section 22.14 prohibits revising the split in any later period.3National Housing Federation. FRS 102 The Financial Reporting Standard Applicable in the UK and Republic of Ireland The equity component is never remeasured, amortized, or revalued. It sits in equity at its original amount until the instrument is converted, redeemed, or otherwise settled.
Allocating Transaction Costs
Directly attributable issue costs (legal fees, advisory fees) are split between the two components in proportion to their relative fair values at issuance.1Croner Navigate. Accounting for Financial Liabilities and Equity Under FRS 102 In the example above, roughly 92.3% would attach to the liability and 7.7% to equity.
The liability portion reduces the initial carrying amount and is amortized through interest expense over the instrument’s life via the effective interest method. The equity portion reduces the Conversion Option Reserve directly. Neither hits profit or loss on day one.
Measuring the Liability After Day One
After initial recognition, the liability is measured at amortized cost using the effective interest method.4Chartered Accountants Ireland. FRS 102 The Financial Reporting Standard Applicable in the UK and Republic of Ireland – Section 11 Basic Financial Instruments Interest expense each period equals the opening carrying amount multiplied by the effective interest rate. In the example, that rate is 8% (the market rate from the initial split), not the 5% coupon.
The amortization schedule for ABC Limited runs as follows:
- Year 1: interest expense £36,907 (£461,343 × 8%), cash interest £25,000, discount amortization £11,907. Closing liability £473,250.
- Year 2: interest expense £37,860 (£473,250 × 8%), cash interest £25,000, discount amortization £12,860. Closing liability £486,110.
- Year 3: interest expense £38,890 (£486,110 × 8%), cash interest £25,000, discount amortization £13,890. Closing liability £500,000.
By maturity the carrying amount has accreted back to £500,000. Total discount amortized over three years is £38,657, which is exactly the equity component recognized at inception. That equality is a mathematical consequence of the residual method, not a coincidence. Total reported interest expense over the life of the instrument is £113,657 (£75,000 cash coupons plus £38,657 non-cash discount amortization), even though only £75,000 of cash leaves the business.
This is the point that catches preparers out. Reported interest expense exceeds the cash coupon, which depresses profit compared with how the instrument would look if accounted for as a single debt at face. Anyone modelling debt service coverage or interest cover on the issuer needs to know the effective interest method is inflating the finance-cost line.
Conversion, Redemption, and Modification
Conversion Into Equity
When the holder converts, both the liability and the equity component are derecognized and reclassified into share capital and share premium. No gain or loss passes through profit or loss. The liability’s carrying amount at the conversion date plus the original equity component together form the total credited to share capital and share premium.
FRS 102 does not spell out the detailed mechanics of extinguishing the liability on conversion.1Croner Navigate. Accounting for Financial Liabilities and Equity Under FRS 102 Most preparers treat conversion as an equity-only transaction, transferring the combined carrying amounts into the share accounts without any income statement effect. Where doubt exists, many look to IAS 32 for analogous guidance as an accounting policy choice.
Cash Redemption Before Maturity
If the issuer redeems for cash, the liability is derecognized at its carrying amount on the redemption date. Any difference between the cash paid and that carrying amount is recognized immediately as a gain or loss in profit or loss. The original equity component is reclassified from the Conversion Option Reserve into retained earnings or another equity reserve. It does not pass through the income statement.
Modification of Terms
Changes to the conversion ratio, maturity, or interest rate can trigger derecognition of the original liability if the modification is substantial. A substantial modification is treated as extinguishment of the old liability and recognition of a new one.5HM Revenue & Customs. Corporate Finance Manual – New UK GAAP: FRS 102: Derecognition of Financial Liabilities The new liability is measured at fair value using the market rate at the modification date, and a fresh residual-method split is performed. Any difference between the old carrying amount and the new fair value goes to profit or loss.
Deferred Tax
Split accounting creates a temporary difference many preparers miss. At inception, the liability’s carrying amount (£461,343 in the worked example) is lower than its tax base, which is generally the full face value (£500,000) because tax authorities treat the whole instrument as debt. That difference produces a deferred tax asset on the liability side, with the corresponding charge taken against the equity component rather than profit or loss, following the principle that tax effects track the transaction that produced them.
As the discount amortizes and the carrying amount accretes toward face value, the temporary difference unwinds and the deferred tax asset reverses over the instrument’s life. Booking this adjustment through profit or loss in the year of issue instead of against equity produces an unexpected earnings hit.
Presentation and Disclosure
The liability sits within non-current liabilities (or current, if maturity is within twelve months) at amortized cost. The equity component sits in a dedicated reserve within equity, separate from share capital and retained earnings. The two are presented separately; netting them defeats the point of the split.
Effective interest expense is reported as a finance cost. Some preparers add a note reconciling cash interest paid to total interest expense recognized, though it isn’t strictly required.
Section 11.48A sets out the disclosure requirements. Where a convertible contains multiple features that substantially modify cash flows and are interdependent, such as a callable convertible, the entity must disclose the existence of those features.6Accurri. FRS 102 The Financial Reporting Standard Applicable in the UK and Republic of Ireland The wider financial-instruments disclosures cover credit risk, liquidity risk, market risk, and how the entity manages those exposures.
Most preparers also disclose the effective interest rate applied to the liability, the key conversion terms (ratio, price, exercise window), and a reconciliation of movements in both components during the period. That gives users enough to understand the instrument’s impact and model future cash flows.