2026 UK & US Tax Rules: Updated for Cross-Border Taxpayers

If you live, work, or invest across the United Kingdom and the United States, 2026 is a year when both tax systems matter at once. On the UK side, the 2026–27 tax year (from 6 April 2026) brings a higher dividend tax charge, continued freezing of the personal allowance, and further steps in the post–non-dom residence-based regime. On the US side, the One Big Beautiful Bill Act (OBBBA) made permanent many individual provisions that were due to expire — keeping the TCJA rate structure in place while adding temporary deductions for tips, overtime, and seniors. This guide summarises the main UK and US tax rule updates for 2026, with particular relevance for Americans in the UK and Britons with US assets or filing obligations. It is general information only and does not replace personalised advice from a qualified cross-border tax adviser.

UK tax rules for 2026–27

The UK tax year runs from 6 April to 5 April. For 2026–27, headline income tax rates are unchanged at 20%, 40%, and 45%, but several thresholds and charges have shifted — or stayed frozen — in ways that affect take-home pay and investment returns.

Personal allowance and income tax bands

The standard personal allowance remains £12,570 for 2026–27, with the basic rate limit fixed at £37,700. The higher rate threshold (personal allowance plus basic rate band) stays at £50,270. The allowance tapers by £1 for every £2 of adjusted net income above £100,000, disappearing entirely at £125,140. Freezing these thresholds — now extended beyond 2027–28 in legislation — means more taxpayers are pulled into higher bands as nominal incomes rise, a phenomenon often called fiscal drag.

Dividend tax: the main UK change for 2026

From 6 April 2026, the most material change for many UK investors and company directors is the rise in dividend tax rates. The £500 dividend allowance is unchanged, but rates on dividends above that allowance increase by 2 percentage points:

• Basic rate — rises from 8.75% to 10.75% on dividends within the basic rate band.
• Higher rate — rises from 33.75% to 35.75% on dividends within the higher rate band.
• Additional rate — remains 39.35% (unchanged).

For a higher-rate director taking £50,000 in dividends after the allowance, the extra tax can run to several hundred pounds a year. ISAs, pension contributions, and spouse income allocation become more valuable planning tools — particularly where one spouse remains in the basic rate band.

Capital gains, carried interest, and reliefs

Main CGT rates on most assets remain 18% (basic rate) and 24% (higher rate) for 2026–27. The annual exempt amount stays at £3,000 for individuals. Business Asset Disposal Relief and Investors' Relief rates rise from 14% to 18% from April 2026 — a notable change for founders and long-term investors who relied on the lower rate. Carried interest moves fully into the Income Tax framework from 6 April 2026, ending the separate CGT treatment that applied previously. For US citizens, UK gains may still be reportable on Form 1040 and potentially subject to US tax after foreign tax credits.

Non-dom reforms and the four-year FIG regime

The UK's remittance basis was abolished for most purposes from 6 April 2025, replaced by a residence-based system. New arrivals who have been non-UK resident for at least ten years may qualify for the four-year foreign income and gains (FIG) regime — exempting certain foreign income and gains from UK tax for up to four years, provided funds are not remitted to the UK. US citizens cannot use the FIG regime for US tax purposes: the IRS taxes worldwide income regardless. A UK election that exempts foreign income locally may create a mismatch where US tax is still due, making coordination between SA100 and Form 1040 essential.

When both UK and US rules apply

US citizenship and green-card status trigger ongoing US filing obligations regardless of UK residence. The two systems do not simply add together — planning focuses on how income is characterised, which country taxes it first, and how double tax is relieved:

• Foreign earned income exclusion (FEIE) and housing exclusion — for qualifying bona fide UK residents, up to prescribed dollar limits on earned income.
• Foreign tax credit (FTC) — UK income tax and National Insurance may offset US tax on the same income, with carry-forward rules.
• US–UK tax treaty — affects which country taxes pensions, directors' fees, property income, and how relief is applied.
• UK dividend rate rises do not reduce US tax automatically — US citizens report dividends on Form 1040 and claim FTC for UK tax paid.
• FBAR and FATCA — reporting foreign accounts remains separate from income tax but is equally important for compliance.

Key deadlines for 2026

• 6 April 2026 — UK 2026–27 tax year begins; new dividend rates and CGT relief changes take effect.
• 31 January 2027 — UK Self Assessment online filing and payment deadline for 2025–26 tax year.
• 15 April 2027 — US federal return and payment deadline for tax year 2026 (automatic extension to 15 June for taxpayers abroad).
• 15 October 2027 — extended US filing deadline if an extension was filed on time.
• 15 April 2026 — first estimated US tax payment for tax year 2026.

Frequently asked questions