Tax Diary December 2026/January 2027

December 2026

1 December 2026 - Due date for Corporation Tax payable by companies with an accounting period ended 28 February 2026, unless the company is required to pay Corporation Tax by instalments. 7 December 2026 - VAT returns and payments are normally due for VAT accounting periods ended 31 October 2026, unless an alternative deadline applies, for example under the Annual Accounting Scheme. 19 December 2026 - PAYE and National Insurance deductions for the month ended 5 December 2026 must normally reach HMRC by this date where payment is made by post. As 19 December falls on a Saturday, postal payments should reach HMRC by Friday 18 December. Where payment is made electronically, the normal deadline is 22 December 2026. 19 December 2026 - Filing deadline for the CIS300 monthly return for the month ended 5 December 2026. 19 December 2026 - CIS tax deducted for the month ended 5 December 2026 must normally reach HMRC by this date if payment is made by post. As 19 December falls on a Saturday, postal payments should reach HMRC by Friday 18 December. Where payment is made electronically, the normal deadline is 22 December 2026. 30 December 2026 - Deadline for filing the 2025-26 Self-Assessment tax return online where an individual wants HMRC to collect a Self-Assessment liability of less than £3,000 through their PAYE tax code, subject to HMRC's normal conditions. 31 December 2026 - Companies with an accounting period ended 31 December 2025 must normally submit their Corporation Tax return to HMRC by this date. 31 December 2026 - Private companies with an accounting period ended 31 March 2026 will normally need to file their accounts at Companies House by this date. Different deadlines can apply to a company's first accounts or where the accounting reference date has been changed.

January 2027

1 January 2027 - Due date for Corporation Tax payable by companies with an accounting period ended 31 March 2026, unless the company is required to pay Corporation Tax by instalments. As 1 January is a bank holiday, companies should arrange payment in advance to ensure that HMRC receives cleared funds on time. 7 January 2027 - VAT returns and payments are normally due for VAT accounting periods ended 30 November 2026, unless an alternative deadline applies, for example under the Annual Accounting Scheme. 14 January 2027 - Deadline for submitting CT61 returns and paying Income Tax deducted from relevant payments, including certain interest payments made by companies, for the quarter ended 31 December 2026. 19 January 2027 - PAYE and National Insurance deductions for the month ended 5 January 2027 must reach HMRC by this date where payment is made by post. Where payment is made electronically, the normal deadline is 22 January 2027. 19 January 2027 - Filing deadline for the CIS300 monthly return for the month ended 5 January 2027. 19 January 2027 - CIS tax deducted for the month ended 5 January 2027 must reach HMRC by this date if payment is made by post. Where payment is made electronically, the normal deadline is 22 January 2027. 31 January 2027 - Deadline for submitting online Self-Assessment tax returns for the tax year ended 5 April 2026. As this date falls on a Sunday, taxpayers should allow sufficient time to complete and submit their returns. 31 January 2027 - Due date for payment of any outstanding Self-Assessment Income Tax and Class 4 National Insurance liabilities for 2025-26, together with the first payment on account for 2026-27 where applicable. Taxpayers should ensure that payments reach HMRC by the deadline. 31 January 2027 - Companies with an accounting period ended 31 January 2026 must normally submit their Corporation Tax return to HMRC by this date. 31 January 2027 - Private companies with an accounting period ended 30 April 2026 will normally need to file their accounts at Companies House by this date. Different deadlines can apply to a company's first accounts or where the accounting reference date has been changed.

Other deadlines to remember

Capital Gains Tax on most disposals of UK residential property must normally be reported and paid within 60 days of completion. The actual deadline therefore depends upon the completion date rather than being a fixed monthly diary date.

Employers should also remember that Full Payment Submissions under PAYE Real Time Information are normally required on or before the date employees are paid. Special reporting arrangements may apply where employees are paid earlier than usual because of Christmas or New Year holidays.

Companies House confirmation statements must normally be filed within 14 days of the end of the company's review period. The deadline depends upon the company's individual confirmation statement date rather than its accounting year end.

Making Tax Digital for Income Tax requires quarterly updates from individuals within the new reporting regime. The next standard quarterly update deadline for the 2026-27 tax year is 7 February 2027 for taxpayers using the tax-year reporting periods. Different dates can apply where calendar quarters are used.

Corporation Tax payment and filing deadlines are not the same. Most companies must pay Corporation Tax nine months and one day after the end of their accounting period, while the Corporation Tax return is normally due 12 months after the accounting period ends. Larger companies may be required to make quarterly instalment payments.