What is the UK tax year?
Updated on June 23, 2025
by Clark Stott
Reviewed by: Aya Takriti
Table of Contents
What Americans need to know about the UK tax year 2025-2026
If you’re a US expat in the UK, one important thing to understand is that the UK tax year starts at a later time than in the US.
That’s because the US follows the calendar year, which starts on January 1 and ends on December 31. The UK does not follow this.
But it’s not just about the dates. This difference can affect how and when you report income to both tax authorities.
It’s a huge advantage if you know how to navigate the UK tax year, alongside the US tax year. This can help you comply with both countries and avoid paying tax twice.
What date does the UK tax year start?
The UK tax year starts on April 6 each year. You can begin reporting income, expenses, and taxes to His Majesty’s Revenue & Customs (HMRC).
What date does the UK tax year end?
The UK tax year ends on April 5 of the following year. By this time, you should have your records and forms ready to file with the HMRC.
What are income tax weeks in the UK?
When April 6 starts in the UK, the whole year is then broken into “tax weeks,” which are just seven-day periods used to help manage taxes, especially for:
- Weekly-paid Employees: If you get paid every week, your tax and National Insurance are worked out based on each of these tax weeks.
- Employers using PAYE (Pay As You Earn): Used to calculate and report wages, taxes, and deductions to HMRC, plus figure out how much National Insurance to deduct from your wages.
Tax weeks are like a built-in calendar for UK payroll; there are usually 52 or 53 tax weeks in a year. This setup ensures that the right amount of tax is taken from your wages and that everything is handled fairly and consistently.
What are the PAYE deadlines in the UK?
Here are the UK tax year deadlines for American expats
|
Due Date |
Event or Requirement |
|
19th of every month |
Deadline for PAYE & NICs payments (non-electronic) |
|
22nd of every month |
Deadline for electronic PAYE & NICs payments |
|
May 31, 2025 |
Issuance of P60s to employees for the 2024-2025 tax year |
|
July 6, 2025 |
Deadline for the P11D forms submission (expenses & benefits for employees) |
|
July 19, 2025 |
Class 1A NICs postal payments deadline (on benefits reported in P11Ds) |
|
July 22, 2025 |
Class 1A NICs electronic payments deadline (on benefits reported in P11Ds) |
What is the deadline for claiming a tax refund?
The deadline to claim a tax refund is within 4 years from the end of the tax year in which you overpaid tax.
So, the deadline for the tax year 2024-2025 is April 05, 2029.
Need help with your US tax obligations in the UK?
Ask us anything and we’ll provide solutions.
What is the Capital Gains Tax (CGT) payment deadline in the UK?
It will depend on the asset you sold:
|
Type of Asset |
When CGT Must Be Paid |
|
UK residential property |
Within 60 days after selling the property |
|
Other assets |
By January 31 following the tax year |
When can I register for Self-Assessment?
For US citizens who are new taxpayers in the UK or are self-employed, you can register for Self-Assessment until October 31, 2025.
📌 Important! Many UK residents don’t need to file for Self-Assessment because taxes are usually deducted automatically through the PAYE (Pay As You Earn) system.
When is the Self-Assessment deadline for 2025-2026?
The deadline for the Self-Assessment paper return is October 31, 2025.
The deadline for the online Self-Assessment tax return is January 31, 2026.
Are there different tax year dates for different entities?
Yes, here’s a general guide:
- Individuals & self-employed – April 06 of the current year to April 05 of the next year
- Companies – Determined by the company’s accounting period
- Government – Runs from April 01 to March 31
How can I prepare for the end of the tax year?
As a US expat, aligning your US and UK tax filings can yield you the best results. Here’s how you can do it:
- Use IRS Form 1116 (Foreign Tax Credit): The IRS wants proof that the foreign taxes you claim as a credit were paid on income earned during the right tax year. You can:
- Pro-rate your income: Split the UK income to match the US calendar year. Or
- Use the accrual method: Report your UK taxes in the year the income was earned, even if you paid the tax later.
- Maximize UK tax-free allowances: Depending on your eligibility, you can use the Personal Allowance, Dividend Allowance, or ISA Allowance before they reset.
📌 Tip! A tax expert can help you adjust your tax reporting so that UK taxes paid are properly credited on your US return, avoiding double taxation.
If you want to know more about aligning your UK and US taxes, check out our comparison of US and UK taxes. You’ll be able to see the difference between the two tax systems.
FAQ'S
-
Are there penalties for late filing and payment in the UK?
Yes, there are. If you miss the Self Assessment deadline, HMRC charges a £100 late filing penalty, even if you don’t owe any tax. Further penalties will apply if your return is over 3 months. Late payment interest also accrues daily.
-
How do I know if I need to complete a self-assessment tax return?
-
What is the UK personal allowance for 2025 to 2026?
-
Do I need to report UK income on my US tax return?
-
What is HMRC’s PAYE system?
Prefer to talk it through? Schedule your free callback today.
Spread the word. Please share… 👉
