Introduction: Why Fiscal Drag Hits Americans in Britain Twice
Fiscal drag is the extra tax you pay when your income rises but the thresholds that decide your tax rate stay still, and Britain has now frozen its main income tax thresholds until April 2031. For a British colleague, that is one problem. For an American in London, it is two. The United States indexes its tax brackets every year, while the United Kingdom does not. Consequently, your UK bill climbs faster than your US bill, and the gap between them is money that no tax credit ever returns.
Most articles on fiscal drag stop at the British side. They show how many people now pay higher-rate tax and suggest a pension contribution. However, none of them asks what happens on Form 1040. That omission matters, because the usual UK remedies work differently, and sometimes not at all, once a US return sits beside the UK one.
This guide to fiscal drag therefore covers both returns. It sets out which thresholds are frozen, what the freeze costs at different income levels and why the foreign tax credit does not cushion the blow. Furthermore, it identifies the American thresholds that never move either. At TaxYork, we prepare US and UK returns side by side for high earners, so the figures below reflect what we see in real filings.
Fiscal Drag Explained: The Frozen Thresholds to April 2031
How Fiscal Drag Works in Practice
Fiscal drag needs no change in tax rates. It needs only inflation, pay rises and a threshold that stays put. For example, a 5% pay rise that merely matches rising prices leaves your spending power unchanged. Nevertheless, more of your salary now sits in a higher band, so your average tax rate goes up. Economists also call the effect bracket creep.
Governments like fiscal drag because it is quiet. No Chancellor has to announce a higher rate. Instead, the yield grows each year by itself. Accordingly, critics describe the policy as a stealth tax.
Which UK Thresholds Are Frozen
The personal allowance has stood at £12,570 since April 2021, and the higher-rate threshold at £50,270. The current income tax rates and bands confirm both figures for 2026/27. Moreover, the additional-rate threshold fell from £150,000 to £125,140 in April 2023 and has not moved since.
The freeze was first due to end in 2026. It was then extended to 2028. Subsequently, the Budget 2025 document extended it again to April 2031, together with the main National Insurance thresholds. As a result, the allowance will have stood still for a full decade.
Some figures have been frozen for longer. In particular, the £100,000 point at which the personal allowance starts to taper away dates from April 2010 and has never been uprated. Had it tracked inflation, it would now sit above £150,000.
How Much Revenue the Freeze Raises
The revenue from fiscal drag is large. The Office for Budget Responsibility's November 2025 outlook forecasts that the share of taxpayers paying the higher or additional rate will rise from 15% in 2021/22 to 24% in 2030/31. Additionally, it expects about 4.8 million more people to reach the higher rate and 600,000 more to reach the additional rate over that period.
HMRC estimates that just over two million people will earn more than £100,000 in 2026/27, against about 1.2 million five years earlier. Therefore the group that once counted as the very top is now a broad band of senior professionals. Most Americans working in the City, in law or in technology sit inside it.
The Allowances That Shrank Instead of Freezing
Several allowances went backwards, which deepens fiscal drag for investors. The dividend allowance fell from £2,000 to £500, as the GOV.UK dividend tax guidance shows. Similarly, the capital gains annual exempt amount dropped from £12,300 to £3,000. Meanwhile, the personal savings allowance has been £500 for higher-rate taxpayers since 2016, and additional-rate taxpayers receive none.
Rates are rising on top. Dividend rates went up by two points in April 2026, to 10.75% and 35.75% below the unchanged 39.35% additional rate. Furthermore, savings and property income will carry rates of 22%, 42% and 47% from April 2027. Investors therefore face higher rates and smaller allowances together.
What Fiscal Drag Costs at Six-Figure Incomes
The Step From 40% to 60%
The most expensive effect of fiscal drag appears between £100,000 and £125,140. In that range, you lose £1 of personal allowance for every £2 of income. Consequently, each extra £100 costs £40 of tax on itself and £20 on the allowance withdrawn. The effective rate is 60%, or 62% with National Insurance.
The test uses adjusted net income, which HMRC defines in its adjusted net income guidance. It covers salary, bonus, benefits, rental profit, dividends and interest, less pension contributions and Gift Aid. Importantly, it also includes foreign income. An American with a US brokerage account can therefore cross £100,000 on a salary of £90,000.
The Cliff Edges Beyond Tax
Other rules key off the same figures. For example, Tax-Free Childcare and funded nursery hours end entirely once either parent's adjusted net income passes £100,000. That is a cliff, not a taper. Likewise, the High Income Child Benefit Charge claws back child benefit between £60,000 and £80,000.
Pensions carry a similar trap higher up. The pension annual allowance of £60,000 starts to taper once adjusted income exceeds £260,000, and those limits are fixed in cash terms too. As pay rises, fiscal drag moves more people into each of these zones without any real increase in wealth.
Scotland Adds a Further Layer
Scottish taxpayers face six bands and a top rate of 48%, so the same freeze bites harder north of the border. In the taper zone, the effective Scottish rate reaches 67.5%. Our guide to Scottish income tax and the foreign tax credit covers that position in detail.
Why the US Return Does Not Soften Fiscal Drag
America Indexes and Britain Does Not
The United States adjusts its brackets and standard deduction for inflation every year. The IRS inflation adjustments for tax year 2026 set the single standard deduction at $16,100, up from $12,550 in 2021. Likewise, the 24% bracket for a single filer now begins at $105,700, against $86,375 five years ago, as the 2026 federal bracket tables show.
The result is a widening gap, and fiscal drag explains all of it. Your US tax on a salary that rises with inflation stays roughly level as a share of income. In contrast, your UK tax on the same salary climbs every year. Fiscal drag is therefore a British charge with no American counterpart on earned income.
Excess Credits Grow but Never Pay Out
Americans in Britain usually relieve double tax through the foreign tax credit. The credit is capped at the US tax on the same foreign income under section 904 of the Internal Revenue Code. Because UK tax on a six-figure salary already exceeds the US tax, the credit already wipes out the US bill. Every extra pound of UK tax above that level simply adds to an unused balance.
That balance has little value. Unused credits carry forward for ten years, but only against US tax on foreign income in the same category. Therefore a banker with rising general-category credits from salary cannot use them against passive income such as dividends. For most long-term UK residents, the carryover expires unused. Hence the IRS shares none of the cost of fiscal drag. Our tax treaty and foreign tax credit service tracks those carryovers by category on Form 1116.
The Exclusion Offers No Escape
Some Americans use the foreign earned income exclusion instead. The exclusion is indexed and stands at $132,900 for 2026. However, it changes nothing on the UK side. It only removes income from a US return that would have owed little or nothing after credits anyway. For a high earner, the exclusion and the credit both end in the same place: full UK tax and almost no US tax on salary.
America Has Its Own Frozen Thresholds
The United States is not blameless. Several thresholds that matter to this audience are fixed by statute and never indexed. For instance, the 3.8% net investment income tax applies above $200,000 for a single filer and $250,000 for a joint return, and those figures date from 2013. A married American who files separately from a non-American spouse has a threshold of only $125,000.
Similarly, the 0.9% Additional Medicare Tax starts at $200,000 and has never moved. Moreover, the $10,000 trigger for the FBAR has stood for decades. Importantly, no foreign tax credit reduces the net investment income tax. An American investor in Britain can therefore suffer fiscal drag in both countries at once, on the same dividends.
How Fiscal Drag Reaches Investment Income and Currency
Dollar Income Measured in Pounds
HMRC taxes your worldwide income in sterling. If you hold a US portfolio, your dividends and interest are converted at the rate for the day or the year. Consequently, a weaker pound raises your UK taxable income even when your dollar income is flat. For example, $40,000 of dividends is about £30,100 at $1.33 and £32,000 at $1.25.
That extra £1,900 does not sit in a neutral band. It lands on top of your salary, at 39.35% or inside the 60% taper zone. Currency movement is thus a second engine of fiscal drag for Americans, and one that British guides never mention.
Bonuses and Stock Vesting
Lumpy pay makes fiscal drag worse. A bonus or a block of restricted stock that vests in one tax year can push adjusted net income from £95,000 to £140,000. The allowance then disappears for that year alone. In addition, UK and US tax years differ, so a March bonus falls in one UK year but may share a US calendar year with the following winter's award.
Timing therefore deserves attention. Where an employer offers a choice of vesting date or bonus deferral, the UK tax year end on 5 April is the date that matters. The US position rarely changes, because credits cover the salary either way.
The Four-Year Regime Interacts Too
New arrivals who claim the four-year foreign income and gains regime give up the personal allowance for each year of claim. At incomes above £125,140, that costs nothing, because the allowance has already gone. However, as the freeze drags more arrivals above that line, the regime becomes cheaper to claim. Our cross-border planning service models that choice year by year.
Reducing the Cost of Fiscal Drag Across Both Returns
Pension Contributions Work on Both Sides
A pension contribution is the standard British answer to fiscal drag, and for Americans it is the strongest one. A contribution reduces adjusted net income, so it restores the personal allowance and can save 60% in the taper zone. Furthermore, the US-UK tax treaty lets a US citizen who lives and works in Britain exclude or deduct contributions to a UK workplace scheme on the American return, within US plan limits.
The foreign tax credit makes the saving stick. Because you already hold excess credits, a lower UK bill does not raise your US bill. The UK saving is therefore a real saving. In contrast, a taxpayer with no excess credits would see part of it clawed back by the IRS. Salary sacrifice remains effective for now, although National Insurance relief on sacrificed pension contributions above £2,000 a year ends in April 2029.
Gift Aid Helps Britain Only
Gift Aid donations also reduce adjusted net income. However, the United States generally allows no deduction for a gift to a UK charity, because the organisation is not American. Therefore the donation saves UK tax at up to 60% and saves nothing on Form 1040. Given excess credits, that outcome is usually acceptable, but you should know it before you give.
Wrappers That Fail the US Test
British guides tell savers to shelter investment income in an ISA. For an American, that step fails. The United States taxes ISA income in full, and the funds inside are usually passive foreign investment companies with punitive treatment. As a result, the main UK defence against shrinking dividend and savings allowances is closed to you. Direct holdings of individual shares, or US-listed funds held in a taxable account, are the workable alternatives.
Keep the Paperwork Complete
Rising income also pulls people into filing duties. HMRC requires a Self Assessment return when you have untaxed foreign income, such as US dividends, whatever your salary. Likewise, growing UK balances cross US reporting lines. Our US tax returns for expats and FBAR and FATCA reporting services keep both sides aligned, including for clients who have missed earlier years.
Case Study: An American Banker Whose Real Pay Has Not Changed
Daniel is a US citizen who has worked for a London investment bank since 2019. In 2021/22 he earned £95,000. His pay has risen by 5% a year, broadly in line with prices over the period, so in 2026/27 he earns £121,250. He is single and uses the foreign tax credit. All figures are illustrative, with a constant rate of $1.33 to the pound and income tax only.
In 2021/22, Daniel's UK income tax was £25,432, an average rate of 26.8%. In 2026/27, the same thresholds apply to a larger salary. His personal allowance has tapered to £1,945, and his income tax is £40,182, an average rate of 33.1%. His UK tax has therefore grown by 58% while his pay grew by 28%.
Suppose instead that the allowance and the basic-rate band had risen by 23%, roughly matching inflation since 2021. Daniel would keep a full allowance of about £15,460, and his tax would be about £33,040. Fiscal drag therefore costs him roughly £7,100 in this single year.
Now turn to the US return. In 2021, his salary of $126,350 produced federal tax of about $21,300 before credits, an average rate of 16.9%. In 2026, his salary of $161,263 produces about $27,400, an average rate of 17.0%. Indexation has held the US rate level.
The credit position shows the loss. In 2021 his UK tax of about $33,800 exceeded his US tax by $12,500. In 2026 his UK tax of about $53,400 exceeds it by $26,000. His excess credit has doubled, and he will never use it. Every pound of the extra UK tax is a final cost.
Daniel then makes a pension contribution of £21,250 by salary sacrifice. His adjusted net income falls to £100,000, his allowance returns in full and his UK income tax drops to £27,432. The saving is £12,750, exactly 60% of the contribution. On the US side, the treaty keeps the contribution out of his income, and he still holds excess credits. Consequently, the IRS takes none of the saving back.
Finally, without action fiscal drag continues. On the same 5% path, Daniel will earn about £147,400 in 2030/31, when the freeze is due to end. His income tax will be about £52,500, and part of his salary will bear the 45% rate.
How TaxYork Can Help
TaxYork prepares UK and US returns together for investment bankers, investors, company owners and other high earners. We calculate adjusted net income with your US investment income included, so you know where you stand against £100,000 and £125,140 before the tax year ends. Furthermore, we track foreign tax credit carryovers by category, test pension contributions against both sets of rules and prepare the treaty disclosures that support them.
In our experience, the cost of fiscal drag is rarely visible on one return alone. It appears when the two are compared. Therefore we review both each year, and we bring earlier years up to date where filings were missed.
Conclusion
Fiscal drag is not a headline tax rise, but it now runs for a decade. Britain's thresholds stay frozen until April 2031, while its dividend, savings and gains allowances have shrunk. Meanwhile, the United States indexes its brackets, so your US bill barely moves. The difference accumulates as foreign tax credits that expire unused. In addition, America's own fixed thresholds add a charge on investment income that no credit relieves. Pension contributions remain the most effective response, because the treaty supports them on both returns. Above all, measure your position before 5 April, not after it.
Contact Us
If fiscal drag is pushing your income through the £100,000 or £125,140 thresholds, speak to our team before the tax year ends. You can book a consultation online, email hello@taxyork.com or call 020 3488 8606. Alternatively, contact us with your latest payslip and US return, and we will show you where both bills are heading.
Disclaimer
This article provides general information only and reflects the rules in force in October 2026. It is not a substitute for professional guidance on your own circumstances, and tax rates, thresholds and exchange rates change. Professional standards published by bodies such as the Chartered Institute of Taxation and the ICAEW Tax Faculty, and consumer guidance from MoneyHelper, inform our work. For help with your own position, please contact TaxYork on 020 3488 8606 or at hello@taxyork.com before acting.