Introduction: Bond Premium Amortization for the American Holding Gilts
The US tax rule known as bond premium amortization lets you spread the extra price you paid for a bond above its face value against the interest it pays, and for an American living in Britain it rarely works the way the textbooks say. Most guidance on the subject assumes a US investor, a US Treasury note and a US broker who prints the right figure on Form 1099-INT. However, a London-based American who buys gilts or sterling corporate bonds above par faces three tax systems at once: the IRS rules, HMRC rules that ignore the premium entirely, and US currency rules that treat every pound of amortised premium as a separate foreign exchange transaction.
At TaxYork, we prepare US and UK returns for investment bankers, fund principals and business owners whose portfolios hold large blocks of gilts and investment-grade bonds. In our experience, the premium question is where well-advised clients most often lose money without noticing. Specifically, they either make an election they did not need, or they make it by accident through a US brokerage account and then find it binds their sterling bonds too. Therefore, this guide explains how bond premium amortization works, why HMRC does the opposite, and how to decide whether the election helps or hurts you. The IRS spells the word with a z, so we keep that spelling for the technical term throughout.
Why Bond Premium Amortization Matters More Abroad
Bond premium amortization matters more for Americans abroad because the UK taxes the full coupon while the US, after the election, taxes only the coupon less the amortised premium. Consequently, the two countries tax different amounts of income from the same bond every year. For a US resident, the election simply lowers taxable interest. For a UK-resident additional-rate taxpayer, by contrast, the foreign tax credit usually wipes out the regular US tax on gilt interest anyway, so the election saves far less than it appears to.
Moreover, bond premium amortization has become a live issue because high-coupon gilts have traded above par since yields rose in 2022. Issues such as older 4% and 6% gilts still sell for more than £100 per £100 nominal, so a buyer seeking income pays a premium that disappears by redemption. Similarly, many sterling bonds issued by banks and utilities before 2022 carry coupons well above current yields. As a result, bond premium amortization now affects most fixed-income portfolios we see, not a handful of unusual holdings.
How Bond Premium Amortization Works Under Section 171
Bond premium amortization is governed by section 171 of the Internal Revenue Code, which allows a deduction for the premium on a taxable bond if you elect to amortise it. Bond premium is the amount by which your purchase price, after excluding accrued interest, exceeds everything the bond will pay you other than qualified stated interest. In plain terms, it is the part of your price that you will not get back at redemption. Without the election, there is no bond premium amortization, and that amount stays in your cost basis and turns into a loss when the bond matures or you sell it.
The rule is elective for taxable bonds and mandatory for tax-exempt ones. Notably, a muni bought at a premium must be amortised with no deduction, a point we cover in our guide to municipal bond interest for Americans in Britain. For gilts and corporate bonds, however, bond premium amortization is a choice, and it carries consequences well beyond one holding.
The Constant Yield Method
Under the bond premium allocation rules in Treasury Regulation 1.171-2, you do not spread the premium evenly. Instead, you compute your yield to maturity at the purchase price and allocate premium to each accrual period using that constant yield. In each period, the premium allocated equals the coupon received less the yield applied to your adjusted basis at the start of the period. As a result, bond premium amortization is smallest in the early years and grows as the bond approaches maturity.
For example, a 6% gilt bought at 104 with four years left yields about 4.89% a year, compounded twice yearly to match the gilt coupon dates. The first six-month period therefore amortises about £4,588 per £1,000,000 nominal, while the final period amortises about £5,433. Additionally, your basis falls by exactly the amount amortised each period, so it reaches £1,000,000 on the redemption date and no gain or loss arises at maturity.
Callable Bonds and the Yield to Call
Many sterling corporate bonds carry issuer call options, and the call rules in Treasury Regulation 1.171-3 change the calculation. Broadly, you must assume the issuer will exercise a call in whichever way minimises your yield. Consequently, a bond callable at par in two years with ten years to maturity is often amortised to the call date rather than to maturity. If the issuer then does not call, the regulation treats the bond as reissued on the call date, and you recompute amortisation over the remaining term. In our experience, callable bond premium amortization is the part of the rules that spreadsheets built by private banks most often get wrong.
When Premium Exceeds the Interest
Occasionally, the premium allocated to a period exceeds the interest for that period. That happens with step-down coupons and some floating-rate notes. In that case, the regulations treat the excess as a separate deduction, but only up to the interest you included in earlier periods on the same bond. Any remaining excess carries forward to the next accrual period. Accordingly, you cannot use bond premium amortization on one bond to create a loss against your salary or other investment income.
How HMRC Treats a Gilt Bought Above Par
HMRC takes the opposite approach to the IRS, because UK law has no equivalent of bond premium amortization for individuals. Specifically, UK income tax falls on the full coupon you receive, with no deduction for the premium you paid, and the capital loss at redemption is usually worthless. That asymmetry is the heart of the cross-border problem.
Income Tax on the Gross Coupon
A UK resident pays income tax on gilt and corporate bond interest as savings income. For 2026/27, the rates are 20%, 40% and 45%, and the personal savings allowance is £1,000 for basic-rate taxpayers, £500 for higher-rate taxpayers and nothing for additional-rate taxpayers, as explained in the GOV.UK guidance on tax on savings interest. Furthermore, the Budget 2025 document confirmed that savings income rates rise by two percentage points from 6 April 2027, to 22%, 42% and 47%. Therefore, an additional-rate American will pay 47% to HMRC on the full coupon from 2027/28, while the US taxes a smaller, net figure.
No Relief for the Premium at Redemption
Gilts and qualifying corporate bonds are exempt from UK capital gains tax under section 115 of the Taxation of Chargeable Gains Act 1992. Because gains on them are not chargeable, losses on them are not allowable either. Consequently, the £40,000 you lose when a gilt bought at 104 redeems at 100 produces no UK relief at all. Most sterling corporate bonds held by individuals are qualifying corporate bonds, so the same result applies to them. You can trace the detail through HMRC's Capital Gains Manual.
The Accrued Income Scheme Overlay
If you buy between coupon dates, the accrued income scheme adds another layer. HMRC adjusts your taxable income for the interest that built up before your purchase, while the US treats that element as a return of capital that reduces your basis. Importantly, the accrued interest never enters bond premium amortization for US purposes, because the regulations measure premium after excluding it. Our guide to the accrued income scheme for Americans in Britain works through those adjustments in full.
The Currency Layer Nobody Calculates
Bond premium amortization on a sterling bond is not a dollar calculation. Under Treasury Regulation 1.988-2(b)(10), premium on a bond denominated in a foreign currency is computed in that currency and reduces your interest income in that currency. You then translate the reduced interest into dollars in the normal way. In practice, that means you work out the whole amortisation schedule in pounds before you touch an exchange rate.
Amortised Premium as a Return of Principal
The regulation then adds a step most preparers miss. Each slice of amortised premium is treated as a return of principal, so you realise exchange gain or loss on it. You measure that gain or loss by comparing the spot rate when the premium is amortised with the spot rate when you bought the bond. Notably, these exchange gains and losses are ordinary income or loss under section 988, not capital items.
For instance, suppose you bought a gilt when £1 bought $1.30 and amortise £9,288 of premium during a year when the average rate is $1.32. You recognise an exchange gain of about $186 that year, in addition to the reduced interest. Small amounts like that look trivial, yet on a £10 million portfolio they add up, and they appear in no UK statement. Therefore, credible bond premium amortization on a sterling portfolio needs the schedule in pounds plus a separate currency calculation.
What Happens Without the Election
If you skip bond premium amortization and do not elect, the regulation states that the bond premium becomes a market loss when the bond matures. In other words, you recover the premium in one go as a capital loss at redemption, translated at the rate on your purchase date. Meanwhile, exchange gain or loss on the principal itself arises separately when you receive the redemption proceeds. That split between a capital market loss and an ordinary currency result drives the planning discussed below.
The Accidental Election Through a US Broker
The bond premium amortization election is easy to make without meaning to. Under Treasury Regulation 1.171-4, you make it by offsetting interest income with bond premium on a timely filed return for the first year you want it to apply. Attaching a statement is recommended, yet the offset itself is what counts.
How US Brokers Report Premium
US brokers report premium on covered bonds in the boxes of Form 1099-INT, and the reporting regulations presume you have elected to amortise unless you notify the broker otherwise. Consequently, many Americans in London who keep a US brokerage account have filed returns showing the net interest figure for years. If your preparer entered the full interest on Schedule B and then subtracted an adjustment labelled ABP Adjustment, as the Schedule B instructions describe, you have almost certainly elected.
Why the Election Reaches Your Gilts
Once made, the election applies to every taxable bond you hold at the start of that year and every taxable bond you acquire afterwards. Crucially, it does not stop at the US border. Therefore, an American who elected through a Treasury note at a US broker in 2021 must amortise premium on the gilts bought through a UK platform in 2026, even if no UK statement mentions premium at all. In our experience, this is the most common error in bond premium amortization for dual national US UK clients: the election exists on the US account, but nobody applies it to the sterling holdings.
Revoking the Election
You cannot simply stop amortising. Revocation needs the consent of the IRS, which you request through Form 3115, Application for Change in Accounting Method. Accordingly, the decision to start bond premium amortization deserves real modelling, because unwinding it costs time and professional fees. Additionally, the election covers all your bonds, so a choice that suits your US Treasury ladder may not suit your gilts.
Election or No Election: A Decision Framework
The right answer on bond premium amortization for a UK-resident American depends on two questions. First, does UK tax on the coupon already exceed the US tax on it? Second, do you have capital gains that the US taxes but the UK does not? We built the following framework from the returns we prepare, and it works as a step-by-step process.
Step One: Test the Coupon Against Your Foreign Tax Credit
Start by comparing your UK rate on the coupon with your US rate. Gilt interest is UK-source, so the UK tax on it is creditable on Form 1116 in the passive category. If you pay 40% or 45% to HMRC and 37% to the IRS, the credit removes all regular US tax on the coupon whether you elect or not. In that case, bond premium amortization merely reduces your foreign-source income, shrinks the credit limit and increases your excess passive credits. Furthermore, excess credits only help if you have other low-taxed foreign-source passive income within the one-year carryback and ten-year carryforward.
Step Two: Price the Net Investment Income Tax
Next, measure the 3.8% net investment income tax. The IRS position is that foreign tax credits cannot reduce it, so it often survives when regular tax does not. Here, bond premium amortization lowers net investment income by the amortised premium, so the real saving for many UK-resident clients is 3.8% of the premium, not 37%. For example, on a £40,000 premium translated at $1.32, the saving across the life of the bond is roughly $2,000.
Step Three: Look for UK-Exempt Gains the US Taxes
Then examine your capital gains. Gains inside a stocks and shares ISA are free of UK tax under the GOV.UK rules on individual savings accounts, yet the US taxes them in full at up to 20% plus 3.8%. Similarly, gains on gilts bought at par and sold after a rally escape UK tax but not US tax. Because no UK tax arises, no foreign tax credit covers them. Therefore, a capital loss at redemption, which is what you get without the election, can save 23.8% of the premium against those gains. By contrast, the election saves only 3.8% where the UK tax on the coupon is already high.
Step Four: Check the Rest of the Portfolio
Finally, remember that bond premium amortization is portfolio-wide once elected. If you also hold US Treasuries or US corporate bonds bought above par, the premium on those reduces income the UK may tax at a lower effective rate after treaty relief. In that situation, the election can be worth the full US rate on those bonds. Accordingly, we model every bond you own, in both currencies, before recommending either route. You can read how our team approaches the treaty side in our US-UK tax treaty optimisation service.
Case Study: An Investment Banker With a Gilt Bought at 104
The following illustrative case uses realistic figures to show how bond premium amortization plays out on a real decision. Names and details are fictional, but the mechanics are exactly those we apply on client returns.
The Facts
Catherine is an American managing director at an investment bank in London and an additional-rate taxpayer. On a coupon date, she buys £1,000,000 nominal of a 6% gilt with four years to run, paying £1,040,000 when £1 equals $1.30. Her dollar cost is therefore $1,352,000, and the premium is £40,000. She has never filed a US return showing net interest, so she has not elected. Separately, her stocks and shares ISA produces about $60,000 of realised gains each year, which HMRC ignores and the IRS taxes in full.
In the first year, Catherine receives £60,000 of coupons. HMRC charges 45%, or £27,000, on the gross amount with no deduction for premium. The constant yield schedule allocates £9,288 of premium to that year, so her net interest under the election would be £50,712.
The Numbers With the Election
If Catherine elects bond premium amortization, her US interest for year one is £50,712, or $66,940 at an average rate of $1.32. She also reports an ordinary exchange gain of about $186 on the amortised premium. Her tentative US tax on the interest at 37% is $24,768, yet her £27,000 of UK tax, about $35,640, exceeds it, so the foreign tax credit eliminates the regular US tax. Her net investment income tax falls from $3,010 to $2,544, saving $466 in year one. Across four years, the net investment income tax saving totals roughly $2,000. Meanwhile, her excess passive credits grow, but her other passive income is heavily taxed UK dividends, so those credits are likely to expire unused.
The Numbers Without the Election
If Catherine does not elect, she reports the full £60,000 of interest each year, or $79,200 in year one. The foreign tax credit still removes all regular US tax, so the only extra cost is the 3.8% surcharge on the unamortised premium, about $2,000 over the life of the gilt. At redemption, however, she recognises a market loss of £40,000 translated at her purchase rate, a $52,000 capital loss, assuming sterling ends where it started. That loss offsets $52,000 of her ISA gains, which would otherwise cost 23.8%, or $12,376, with no UK credit available.
Consequently, declining bond premium amortization leaves Catherine about $10,000 better off over four years, before allowing for the delay until redemption. However, if she had earlier filed a return reporting net 1099-INT figures from a US broker, she would already be bound by the election, and the comparison would shift to whether revoking it on Form 3115 justifies the cost. That single fact changes the advice entirely, which is why we always review prior returns before advising on premium.
Reporting, FBAR and Missed Years
Bond premium amortization also has to sit correctly inside the wider compliance picture. A sterling bond portfolio raises reporting duties well beyond Schedule B.
Schedule B, Form 1116 and Publication 550
On Schedule B, bond premium amortization appears as follows: you list the full interest for each holding and then subtract the amortised premium as a separate line labelled ABP Adjustment. IRS Publication 550 on investment income sets out that presentation. Moreover, the net interest figure must also flow into Form 1116, because the passive category limitation uses net foreign-source income. Inconsistency between the two forms is a common reason for IRS correspondence on expat returns.
FBAR and Form 8938 for Gilts on UK Platforms
Gilts held through a UK investment platform or private bank sit in a foreign financial account. Consequently, the account counts towards the $10,000 aggregate threshold for the FBAR filed with FinCEN. Additionally, Form 8938 under FATCA applies once your foreign assets exceed $200,000 at year end or $300,000 at any time for a single filer living abroad, or $400,000 and $600,000 for joint filers. In our experience, a gilt portfolio is often the asset that pushes a client over the Form 8938 line for the first time. Our FBAR and FATCA reporting service handles both forms alongside the income tax return.
Catching Up Missed US Tax Returns
Some Americans in Britain hold gilts for years without filing US returns, on the assumption that HMRC has taxed the interest already. That assumption leads to missed US tax returns and a missed FBAR, even where no US tax would have been due. Importantly, the regulation ties the premium election to a timely filed return, so a late return is a weak vehicle for making it. We therefore treat the first return filed on time as the natural election year and plan the earlier years around the default rule. If you need to bring several years up to date, our team explains the options through our IRS Streamlined filing service. Moreover, the IRS overview for US citizens and resident aliens abroad confirms that worldwide interest is reportable whatever HMRC has collected.
How TaxYork Can Help
TaxYork provides comprehensive US tax return preparation for expats and US UK tax returns preparation for individuals with substantial bond portfolios. We build the bond premium amortization schedule for each gilt and sterling bond in pounds, calculate the section 988 currency results, and reconcile them to Schedule B and Form 1116. Additionally, we review your prior returns to establish whether you have already elected through a US broker, because that single fact decides most of the advice.
Furthermore, we prepare the matching UK self assessment return, so the gross coupon taxed by HMRC and the net coupon taxed by the IRS are reported consistently and the foreign tax credit is claimed in full. Our US tax returns service covers the federal return, FBAR and Form 8938 in one engagement. For clients who also hold low-coupon gilts, our guide to UK gilts and US tax explains the market discount side of the same portfolio.
Conclusion
Bond premium amortization looks like a simple US election, yet for an American in Britain it interacts with HMRC rules that ignore the premium, currency rules that split every amortised pound into a separate exchange result, and a foreign tax credit that often makes the election nearly worthless. In many cases, a UK-resident additional-rate taxpayer with UK-exempt gains does better without the election. In others, particularly where US Treasuries bought above par form part of the portfolio, the election earns its keep.
Ultimately, the right approach to bond premium amortization depends on your whole portfolio, your prior returns and the gains you expect to realise. Therefore, we recommend modelling both routes before you file, because once the election is made it binds every taxable bond you own. Above all, make sure your gilts and sterling bonds are reported in full on Schedule B, Form 1116, the FBAR and Form 8938, whichever route you choose.
Contact Us
If you hold gilts or sterling corporate bonds bought above par and want certainty on your US position, contact us for a confidential review. Our team will check whether you have already elected, model both routes on your actual holdings and prepare your US and UK returns together. Email hello@taxyork.com or call 020 3488 8606, or book a consultation online.
Disclaimer
This article provides general information about the US and UK tax treatment of bonds bought above par as understood at the date of publication. It is not tax, legal or investment advice for your specific circumstances, and the case study is illustrative only. Tax rates, exchange rates and IRS and HMRC guidance change, and the right treatment depends on your full portfolio and filing history. You should obtain professional advice before making or revoking any election or filing any return. TaxYork accepts no liability for action taken or not taken on the basis of this article.