UK accountant's 2026 compliance deadline calendar

2026 is one of the most demanding compliance years in recent memory for UK accountants — MTD ITSA entering its first phase, ongoing ECCTA identity verification requirements, and the usual slate of annual and quarterly obligations. Here are the fixed key dates.

January 2026

• 31 January — Self Assessment online filing deadline and payment of tax owed for 2024–25. First payment on account for 2025–26 also due.
• 19 January — PAYE/NIC for month ending 5 January (postal). 22 January for electronic.
• 31 January — Quarterly VAT return deadline for periods ending 31 October (standard method).

April 2026

• 5 April — End of 2025–26 tax year.
• 6 April — MTD ITSA mandatory for clients with qualifying income >£50,000.
• 6 April — New payroll year begins. New tax codes, NI thresholds and rates apply.
• 19 April — Final PAYE submissions for 2025–26 tax year.
• 31 May — P60s must be issued to all employees.

July 2026

• 6 July — P11D and P11D(b) filing deadline for 2025–26. Employers must report benefits and expenses. Employee copies must be provided by this date.
• 19 July — Class 1A NIC payment due (postal). 22 July for electronic.
• 31 July — Second payment on account for Self Assessment 2024–25.

Quarterly VAT filing pattern

VAT-registered businesses file returns monthly, quarterly, or annually depending on their scheme. For standard quarterly filers, returns and payments fall one month and seven days after the quarter end:

• Quarter ending 31 March → return by 7 May
• Quarter ending 30 June → return by 7 August
• Quarter ending 30 September → return by 7 November
• Quarter ending 31 December → return by 7 February

Companies House: rolling deadlines

Annual accounts and confirmation statements have company-specific due dates based on incorporation and accounting reference dates — not fixed calendar dates. Each company's deadline must be tracked individually.