Business expenses when costs have a private element
September 10, 2026
1 October 2026 – Corporation Tax payment is due for companies with an accounting period ending 31 December 2025, unless the company is required to make quarterly instalment payments.
5 October 2026 – Deadline for notifying HMRC of a new liability to Income Tax or Capital Gains Tax for the 2025–26 tax year. This may include registering for Self Assessment if you became self-employed, started receiving taxable rental income or received other income or gains that have not already been taxed.
7 October 2026 – VAT returns and payments are normally due for accounting periods ending 31 August 2026, unless a different deadline applies. Businesses paying by Direct Debit should allow sufficient time for HMRC to collect the payment.
19 October 2026 – PAYE, employee and employer National Insurance contributions, student loan deductions and Construction Industry Scheme deductions are due for the month ended 5 October 2026 if payment is made by post.
19 October 2026 – Deadline for submitting the CIS300 monthly return for the month ended 5 October 2026.
22 October 2026 – Electronic payments of PAYE, National Insurance contributions, student loan deductions and CIS deductions are due for the month ended 5 October 2026.
22 October 2026 – Electronic payment deadline for tax and Class 1B National Insurance contributions due under a PAYE Settlement Agreement for the 2025–26 tax year. The deadline is 19 October 2026 if payment is not made electronically.
31 October 2026 – Deadline for submitting a paper Self Assessment tax return for the year ended 5 April 2026. Taxpayers who miss the paper filing deadline can normally file online by 31 January 2027 instead.
31 October 2026 – Corporation Tax returns are due for companies with an accounting period ending 31 October 2025.
31 October 2026 – Companies House accounts are due for private companies with an accounting period ending 31 January 2026. Different deadlines apply to a company’s first accounts.
31 October 2026 – Plastic Packaging Tax returns and payments are due for the quarter ended 30 September 2026 where the business is registered for the tax.
1 November 2026 – Corporation Tax payment is due for companies with an accounting period ending 31 January 2026, unless the company is required to make quarterly instalment payments.
7 November 2026 – VAT returns and payments are normally due for accounting periods ending 30 September 2026, unless a different deadline applies. Businesses paying by Direct Debit should allow sufficient time for HMRC to collect the payment.
19 November 2026 – PAYE, employee and employer National Insurance contributions, student loan deductions and Construction Industry Scheme deductions are due for the month ended 5 November 2026 if payment is made by post.
19 November 2026 – Deadline for submitting the CIS300 monthly return for the month ended 5 November 2026.
22 November 2026 – Electronic payments of PAYE, National Insurance contributions, student loan deductions and CIS deductions are due for the month ended 5 November 2026. As 22 November 2026 falls on a Sunday, businesses should arrange payment early enough for the cleared funds to reach HMRC by the deadline.
30 November 2026 – Corporation Tax returns are due for companies with an accounting period ending 30 November 2025.
30 November 2026 – Companies House accounts are due for private companies with an accounting period ending 28 February 2026. Different deadlines apply to a company’s first accounts.
