Jonas Adam Mohamed Osman Abdelghafour

IFRS quantitative finance series

Amortised Cost and the Effective Interest Method Under IFRS 9

Amortised cost is a dynamic measurement produced by contractual cash flows, effective interest, repayments and impairment. It is not simply principal outstanding. The effective interest method spreads economics over time in a way that reconciles origination value to expected contractual receipts.

By Jonas Adam Mohamed Osman Abdelghafour · Published 1 September 2026 · Independent educational analysis

Construct the effective yield

The effective interest rate discounts estimated contractual cash flows through expected life to the gross carrying amount at initial recognition. Integral fees, points, transaction costs and premiums or discounts affect the yield rather than being recognised arbitrarily at inception.

Run the roll-forward

Interest revenue, cash receipts, modifications, write-offs and ECL interact with gross and net carrying amounts. Credit-impaired assets require particular attention to the basis on which interest is calculated.

Modifications and derecognition

When contractual terms change, the bank assesses whether the old asset is derecognised. If not, the gross carrying amount may be recalculated using modified cash flows discounted at the original effective interest rate, with a modification gain or loss.

Quantitative expression

Closing amortised cost = opening balance + effective interest − cash received ± modifications − write-offs

Implementation controls

Important: This article explains quantitative and reporting architecture. Banks must apply the complete IFRS requirements, relevant jurisdictional rules and entity-specific accounting policies.

Primary references

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