Key Dates for SMEs in 2025

Running a small business comes with a lot of responsibilities, and managing your finances is at the heart of it all. From filing taxes to paying National Insurance, staying on top of deadlines is essential to avoid penalties and keep your business on track.

In this article, we’ll go through the key tax and financial dates every small business owner in the UK should know for 2025. Whether you’re a sole trader, a limited company, or a VAT-registered business, these dates will help ensure you stay compliant and avoid any unwanted surprises.

1. Sole traders’ tax and National Insurance deadlines

As a sole trader, you’ll pay your income tax and National Insurance contributions in two stages, known as payments on account. These are advance payments made towards your tax bill based on your previous year’s income.

Here are the dates you need to know:

Key dates for sole traders

31st January 2025 – Balance of any tax for the year 2023/24 is due.
31st January 2025 – First payment on account for the tax year 2024/25 is due.
31st July 2025 – Second payment on account for the tax year 2024/25 is due.
31st January 2026 – Balance of any tax for the year 2024/25 is due.
31st January 2026 – First payment on account for the tax year 2025/26 is due.

If you’re struggling to make your payments on time, it’s important to contact HMRC. You can set up a Time to Pay arrangement, which allows you to pay in instalments. However, remember that interest is charged if you pay late, so always try to stay on top of deadlines.

2. Self-Assessment tax returns

Whether you’re a sole trader or in a partnership, you’re required to file a Self-Assessment tax return. This return tells HMRC how much tax you owe based on your business’ income for the year.

Key dates for Self-Assessment

Paper Self-Assessment tax return for the 2024/25 tax year: 31st October 2025
Online Self-Assessment tax return for the 2024/25 tax year: 31st January 2026

If you’re new to self-employment or have become a partner in a business during the 2024/25 tax year, you’ll need to notify HMRC by 5th October 2025 to ensure you’re registered for Self-Assessment.

New to self-employment?

If you started your business in the 2024/25 tax year, you must notify HMRC by 5th October 2025.

New partner in a partnership?

If a new partner has joined your business during the 2024/25 tax year, you’ll need to inform HMRC by 5th October 2025.

Missed the deadline?

You’ll face a £100 fine - plus extra penalties and interest. Here’s how it works:

Immediately: £100 (even if you don’t owe tax)
After three months: +£10 a day up to max £900
After six months: +5% of tax owed or £300 (whichever is greater)
After 12 months: +5% of tax owed or £300 (whichever is greater)

3. Key dates for VAT-registered businesses

If your business is VAT-registered, it’s essential to keep track of VAT return dates and any changes to VAT rates.

VAT return deadlines

If your VAT return period runs in calendar quarters, your deadlines for 2025 are as follows:

7th May 2025 – VAT return and payment for the period ending 31st March 2025.
7th August 2025 – VAT return and payment for the period ending 30th June 2025.
7th October 2025 – VAT return and payment for the period ending 30th September 2025.
7th February 2026 – VAT return and payment for the period ending 31st December 2025.

Remember that annual adjustments for partly exempt traders will be made either on your March or June returns, which are due on 7th May 2025 or 7th August 2025.

Important VAT changes:

1st January 2025 – Private school fees for terms starting on or after 1st January 2025 will now be subject to UK standard-rated VAT, replacing the previous VAT exemption. This change also applies to deposits and prepayments made before 2025.
1st May 2025 – VAT Fuel Scale Charge rates will be updated for VAT return periods starting on or after 1st May 2025. Be sure to check the new rates to stay compliant.

4. Payroll deadlines for employers

If you employ staff, there are important payroll deadlines to remember, including tax and National Insurance payments, as well as reporting employee benefits.

Key payroll dates

6th April 2025 – Update your employee payroll records for the new tax year.
19th April 2025 – Submit your final Full Payment Summary and Employer Payment Summary for the year ending 5th April 2025 and pay any tax/NIC due.
31st May 2025 – Provide P60s to all employees who were working for you on the last day of the tax year (5 April 2025).
6th July 2025 – Report any employee expenses and benefits for the 2024/25 tax year.
19th July 2025 – Pay Class 1A NICs by post; if paying electronically, the deadline is 22nd July 2025.

These payroll dates are vital to stay compliant with HMRC’s reporting and payment requirements, so be sure to keep your records accurate and up to date.

5. National Minimum Wage and Statutory Pay increases

In 2025, several statutory pay rates are due to increase. This includes the National Minimum Wage (NMW), Statutory Sick Pay (SSP), and Statutory Family-related pay. Make sure to update your payroll to reflect these increases.

National Minimum Wage increase (from 1st April 2025)

National Living Wage (for workers aged 21 and over) – Increases to £12.21 per hour (up from £11.44).
For workers aged 18-20 – Increases to £10.00 per hour (up from £8.60).
For workers under 18 – Increases to £7.55 per hour (up from £6.40).
Apprentices – Increases to £7.55 per hour (up from £6.40).

Statutory Family-related pay increase (from 6th April 2025)

Statutory maternity, paternity, adoption, shared parental leave, and parental bereavement leave pay will increase from £184.03 to £187.18 per week.

Statutory Sick Pay (SSP) increase (from April 2025)

SSP will increase from £116.75 per week to £118.75 per week.

To qualify for SSP, workers must earn at least the Lower Earnings Limit (which is £123.00 per week until April 2025). Keep in mind that SSP is only payable after a 3-day waiting period unless the worker has received SSP within the last 8 weeks.

6. Corporation Tax deadlines (for limited companies)

If you run a limited company, you’re required to file your Corporation Tax return and pay any tax due.

Corporation Tax deadlines

9 months after your company’s financial year ends – Your Corporation Tax payment is due. Be sure to check your company’s financial year-end to know the exact date.
12 months after your company’s financial year ends – Your Corporation Tax return is due. This return must be filed with HMRC.

Corporation tax is calculated based on your company’s profits, so it’s important to keep accurate records and file your return on time to avoid penalties.

7. Important changes and adjustments for 2025

Several updates and changes may affect your business in 2025. Stay aware of these changes to ensure you remain compliant and avoid any unexpected tax bills.

1st January 2025 – Private school fees for terms starting on or after 1st January 2025 will now be subject to VAT. This will apply to many deposits and prepayments made in 2024 for 2025 terms.
1st May 2025 – New VAT Fuel Scale Charge rates come into effect, so check for updates to ensure your business remains compliant.

Staying on top of key tax, VAT, and payroll deadlines is essential for the smooth running of your small business in 2025. By planning ahead, as well as submitting and paying on time, you can avoid penalties and focus on what you do best - growing your business.

This article is accurate as of 20th January 2025.