UK tax year dates & deadlines for self-employed professionals & small businesses 2025/2026

It is important to be aware that there is an automatic penalty of £100 if you are late filing your tax return. The tax year runs from 6 April in the current year to 5 April the following As a self-employed professional who owns a small business, your Self-Assessment tax return is a requirement due by 31 January each year. From filing a Confirmation Statement to paying Corporation Tax, there are a handful of dates to remember which are critical to the running of your business.

Read our guide below, created in collaboration with Markel Tax, to find out tax year dates, including Self-Assessment deadlines and requirements.

Self-Assessment tax returns

You must send a tax return if you are:

• self-employed as a ‘sole trader’ and earned more than £1,000 before deducting any-thing for which you can claim tax relief
• a partner in a business partnership

Self-Assessment tax year dates 2025/2026

For the year 2025/2026, the tax year begins on 6th April 2025 and ends on 5th April 2026. HMRC must receive your tax return and any money you owe by the deadlines noted below:

Late tax return penalties

If you miss the Self-Assessment submission deadline, you will receive a penalty of £100 if your tax return is up to 3 months late.

You will have to pay more if your submission is later than 3 months or if you pay your tax bill late, and you will also be charged interest on late payments. GOV.UK provide a tool where you can estimate how much your penalty could be if you are late, here.

If you have a reasonable explanation for late filing, you can appeal against a penalty. A list of reasonable excuses can be found, here.

How are Limited company owners affected?

As a limited company director, you have a legal responsibility to submit various forms and returns to Companies House and to HMRC.

Running a business as a limited company is usually the most tax efficient way, and the limited liability means that your personal possessions and your home are unlikely to be at risk if your business fortunes take a down-turn.

What you need to file as a Limited company director

As a Limited company director, you are required to keep both HMRC and Companies House informed about your business, including changes to contact details, size and turnover.

There are differences between Companies House and HMRC when it comes to filing information:

• Companies House provides your Limited company with an Accounting Reference Date when the company is first incorporated. This date is the last day of the month or the first anniversary of the company’s incorporation, e.g.: Incorporated 12th January 2024 = Accounting Reference Date 31st January 2025.
• For your company tax return and the payment of your Corporation Tax you are assigned an Accounting Period by HMRC. This begins when you start trading and typically ends on your Accounting Reference Date.

The table shows a summary of the important annual dates for limited companies:

Annual Confirmation Statement

The Confirmation Statement is a separate filing requirement which must be submitted at least once each year, providing information about your company, the directors, and other administration arrangements that you might have in place.

It is a criminal offence not to file your Confirmation Statement within 14 days of the end of the review period, which starts on the date of incorporation and ends 12 months later.

CT600 form

The CT600 form is filed with HMRC once per year and contains details about your company’s income, minus any business expenses and tax allowances. The remaining amount is your taxable profit, which will be used to calculate how much corporation tax your company must pay.

Your Limited company’s first Corporation Tax return (CT600) is due to be submitted to HMRC 12 months after your first accounting year-end. Subsequent Corporation Tax returns are due each year within 12 months of the end of your accounting period.

Corporation Tax for Limited companies

If your Limited company made a profit in the accounting period, then you will have to pay Corporation Tax to HMRC (currently 19% for small companies with profits under £50,000), which must be paid within nine months and one day after the end of the accounting period.

You must keep a full record of your accounts for preparing your annual accounts and any tax records. Ensure you claim for all your allowable expenses to help to reduce your Corporation Tax bill.

If your company made a loss during the accounting period, or if the company is not trading, then it will pay no Corporation Tax.

National Insurance Contributions (NICs)

You are required to pay a National Insurance contribution if you earn a salary over £12,570 per annum, which is typically paid monthly.

As a Limited company director, you can pay yourself a combination of salary and dividends to avoid exceeding the NI threshold. However, if you pay yourself above the primary threshold of £12,570 per annum, then you will have to pay Employee’s NI.

If you pay yourself (or any employees or other directors) above the secondary threshold, set at £5,000 for the 2025/2026 year, then your company will have to pay Employer’s NI.

If you go down the route of salary plus dividends, the amount of dividends you are paid must also be paid to any other directors in your Limited company – speak to an accountant for further details.

P60

As a Limited company owner, you must provide your employees and any other company directors with their P60 by May 31st each year.

Your P60 shows the tax that has been deducted from your salary that you have been paid via your Limited company in the tax year, from April 6th to April 5th the following year.

It is important to keep your P60 safe, as you may need to refer to it at a later date for:

• reclaiming any Income Tax or National Insurance that you might have overpaid
• completing your Self-Assessment
• as proof of your income for any applications you need to make for a loan or mortgage
• an application for tax credits

P11D

Directors and employees must receive their P11D before July 6th, after the end of the relevant tax year. 

The P11D is a summary of the ‘benefits in kind’ and expenses (e.g.: company cars or interest-free loans) provided to company directors within a tax year.

You are required to file a P11D with HMRC and keep a copy for your own records even if your Limited company only has one director (you). If no benefits have been provided you need to file a nil P11D or let HMRC know that a P11D is not needed.

PAYE

PAYE information is usually submitted monthly.

As a Limited company director, you will probably want to pay yourself a salary via a PAYE scheme as you are still an employee of the company.

Payment on Account

If you owe any personal tax, you will be required to make payments on account to HMRC each year on the following dates:

• First payment by midnight on January 31st
• Second payment by midnight on July 31st

Payments on account are advance payments to your tax bill, and you must make two payments on account each year unless:

• your last Self-Assessment tax bill was less than £1,000
• you have already paid over 80% of the tax you owe

Self-Assessment

As a director of a Limited company, you must submit an annual Self-Assessment of your personal income and allowances to HMRC by January 31st each year.

Also known as a personal tax return, the Self-Assessment must include details about all your income, dividends paid to you by your Limited company and other income sources such as rental income. Allowances can be claimed for items including personal pension contributions.

Your Self-Assessment is due by January 31st every year, but you can file it earlier as soon as you receive your P60.

Year-end Accounts

You must submit a set of accounts to Companies House each year, at the end of your accounting period, which includes your company’s income statement, statement of financial position, and other accounting information.

Details about your company’s finances must be made public in accordance with the Companies Act 2006 and in accordance with accounting standards.

Your first set of accounts are typically due nine months after your first year-end, or within 21 months of its incorporation date. Subsequent year-end Accounts are then due every 12 months.

VAT Return

If your Limited company is registered for VAT, you will be required to submit your VAT return every quarter (in some cases annually). The threshold for VAT currently stands at £90,000 turnover per annum.

As a VAT registered company, you must add up all the VAT added to your sales, then deduct any VAT you have paid on business expenses.

The standard rate of VAT is 20%. However, there are flat rate VAT schemes (open to businesses with an expected turnover less than £150,000 within a 12-month period), which are sometimes a better option for freelancers and contractors. Speak to your accountant or business advisor to learn more about which VAT scheme is best for you.

Discover help and guidance for self-employed professionals & small businesses, here, or learn more about our tax defence insurance.

Please note: This article provides guidance for information purposes only. It should not be relied upon wholly when making or taking important business decisions – always seek the services of an appropriately qualified professional. The views expressed by websites referenced to are limited to those of the websites, and do not necessarily reflect the views of Markel Direct.