Premium Amortisation on HTM Securities: RBI Rules for TIRM

For a bank holding government securities in the Held-to-Maturity book, one accounting mechanic quietly shapes reported interest income every single year: premium amortisation on HTM securities. Whenever a bank buys a security for more than its face value and parks it in HTM, RBI's investment portfolio rules require that excess to be spread out rather than booked as a loss on day one. Treasury back-office staff, internal auditors and IIBF TIRM candidates alike need to know exactly how this works — and how it differs sharply from the mark-to-market treatment used elsewhere in the investment book.

📊 Why Premium Arises on HTM Securities

A premium arises whenever a bank pays more than the face value of a government security or bond it intends to hold in the Held-to-Maturity category. This typically happens when the coupon rate on the security is higher than the prevailing market yield for a similar residual maturity — investors are willing to pay extra today to lock in that higher running coupon. The reverse situation, where a bank pays less than face value, produces a discount rather than a premium.

Because HTM securities are meant to be carried through to redemption and are not routinely revalued to market, the excess paid over face value cannot simply sit unrecognised on the balance sheet forever. If it were ignored, the bank would show an artificially inflated book value right up to maturity and then face a sudden, unexplained write-down in the final year when the security is redeemed at par. RBI's framework closes this gap by requiring the premium to be recognised gradually.

This is conceptually distinct from the shifting of investment categories rules, which govern when a security can move between HTM, AFS and HFT. Premium amortisation applies purely to securities that stay put in HTM for the whole holding period, and it has nothing to do with reclassification triggers or the caps that limit how often a bank can shift securities between books.

📜 RBI's 2023 Investment Portfolio Directions and the Amortisation Rule

The governing rule sits inside RBI's Master Direction – Classification, Valuation and Operation of Investment Portfolio of Commercial Banks (Directions), 2023, notified in September 2023 and made applicable to all commercial banks (excluding Regional Rural Banks) from April 1, 2024. This overhaul replaced the older, more prescriptive investment classification circular with a principle-based framework covering HTM, AFS and Fair Value Through Profit and Loss categories, tighter conditions for HTM transfers and sales, and symmetric recognition of gains and losses across categories.

On premium and discount specifically, the direction states that any premium or discount on securities held under HTM must be amortised or accreted, as applicable, over the remaining period to maturity of the instrument. This single line has real operational consequences: treasury back-office teams must build amortisation schedules for every HTM security at the time of acquisition, not adjust the figure only at year-end.

Candidates studying the Money Market chapter will recognise this as part of the broader shift RBI made to align Indian bank investment accounting more closely with global fair-value and amortised-cost conventions, while still preserving HTM as a stable, cost-anchored category for the SLR-heavy G-Sec portfolio most Indian banks carry.

🧮 How Banks Compute and Book the Amortised Premium

Mechanically, the premium (purchase price minus face value) is spread evenly, or on an effective-yield basis depending on the bank's board-approved investment policy, across the number of years or coupon periods remaining until redemption. Each period, a portion of the premium is written off, so the book value of the security steadily declines from its cost price towards its face value — reaching exactly par on the maturity date.

In the financial statements, this amortised amount is not treated as a standalone write-off. RBI's direction specifies it is reflected under Schedule 13 — "Interest Earned" (specifically under the "Income on Investments" head), with a corresponding contra entry in Schedule 8 — "Investments". In effect, the amortisation charge is netted against the interest income the bank earns on that security, rather than appearing as a separate expense line.

Discount works the opposite way: where a security is bought below face value, the discount is accreted — added back — to interest income over the remaining life, so the book value rises gradually to par. Getting the direction right (premium reduces income, discount adds to income) is one of the most commonly tested points in this area of the 5 TIRM VQ Debt Markets & Fixed Income Securities chapter.

💡 Exam Tip: If a question asks how HTM premium affects reported interest income, the answer is always a reduction — amortisation of premium is a drag on income, never an addition.

⚖️ Premium Amortisation vs Mark-to-Market: HTM vs AFS vs HFT

The single biggest exam trap in this area is assuming every investment category treats premium the same way. It does not. HTM securities are carried at amortised cost, so premium amortisation is the correct and only mechanism for recognising that cost gap over time. AFS and HFT securities, by contrast, are not amortised in the same sense — they are periodically fair valued, and the resulting gains or losses flow through either the Available for Sale reserve or the Profit and Loss account depending on the category and RBI's symmetric gain/loss recognition rules.

This is why banks generally prefer parking large, held-till-redemption SLR holdings in HTM: it insulates reported profit from day-to-day yield volatility, replacing it with a smooth, predictable amortisation charge instead. The trade-off is reduced flexibility — HTM securities face tighter conditions on transfers and sales compared with AFS or HFT.

Readers who have already studied mark to market valuation of investments will notice the contrast immediately: mark-to-market answers "what is this security worth today," while premium amortisation answers "how do we recognise a cost that was locked in on day one." Both concepts sit inside the same investment portfolio framework but solve different accounting problems.

⚠️ Common Mistake: Students often assume HTM securities are never revalued at all. They are simply not marked to market for reporting purposes — but a premium is still systematically written down through amortisation, which is a form of value adjustment.

💰 Why This Matters for Bank Profitability and IIBF TIRM Candidates

Premium amortisation directly dents the reported yield a bank earns on its HTM book. A G-Sec bought at a premium because its coupon is above current market yields will, after amortisation, show an effective yield much closer to the prevailing market rate — exactly as intended, since the premium was the market's way of pricing in that extra coupon. Treasury and ALM teams build this into their yield projections; ignoring it would overstate expected investment income for the year.

For exam purposes, this topic frequently overlaps with questions on the broader Setting up a risk organization chapter, since accurate income recognition on the investment book feeds directly into ALCO's assessment of net interest margin. It also connects conceptually to leverage and profitability analysis taught in related CAIIB papers — see how amortisation-style adjustments parallel the treatment of fixed versus variable costs in operating leverage and financial leverage, another area where a cost recognised today changes the shape of reported earnings over several future periods.

Banks disclose their accounting policy on premium/discount amortisation in the notes to accounts of their annual financial statements, and statutory auditors specifically verify that the amortisation schedule for each HTM security matches its remaining tenor at acquisition — not the original tenor, which would understate the charge in later years.

📌 Remember: Premium amortisation only applies to HTM. The moment a security is validly shifted out of HTM, it switches to fair-value accounting and amortisation stops.

🧠 Practice MCQs: Premium Amortisation on HTM Securities

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❓ Frequently Asked Questions

Keep This on Your TIRM Revision List

Premium amortisation on HTM securities is a small mechanic with an outsized presence in TIRM papers because it links accounting treatment, investment policy and yield calculation in one place. Revisit the Treasury Investment and Risk Management tag hub for more topic-wise breakdowns, check the latest benchmark rates at RBI rates resource page, and consult RBI's own Master Directions repository for the full text of the 2023 investment portfolio directions before your exam.