Deadlines · Updated 24 September 2026

UK Accounting Firm Deadlines Calendar 2026

Every key UK deadline for accounting firms in 2026: accounts, CT600, confirmation statements, VAT, Self Assessment, payroll and MTD for Income Tax.

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Key takeaways

Most company deadlines depend on each client's year end — track them per client.
Self Assessment online deadline: 31 January 2026 and 31 January 2027.
MTD for Income Tax started on 6 April 2026 for qualifying income over £50,000.

Company deadlines (per client)

These run from each company's accounting reference date:

Private company accounts to Companies House: 9 months after year end
Corporation Tax payment: 9 months and 1 day after year end (for most companies)
CT600 return: 12 months after the end of the accounting period
Confirmation statement: within 14 days after the review date

VAT

For standard quarterly VAT, the return and payment are due 1 month and 7 days after the end of the VAT period.

Self Assessment

31 January 2026: online returns for 2024/25 and balancing payment, plus first payment on account for 2025/26
5 October 2026: register for Self Assessment for 2025/26
31 October 2026: paper returns for 2025/26
31 July 2026: second payment on account for 2025/26
31 January 2027: online returns for 2025/26

Payroll

FPS: on or before each payday
EPS: by the 19th of the following tax month
PAYE payment: by the 22nd if paying electronically
P60s to employees: by 31 May
P11D and P11D(b): by 6 July

MTD for Income Tax

From 6 April 2026, sole traders and landlords with qualifying income over £50,000 must keep digital records and send quarterly updates. The threshold falls to £30,000 from April 2027 and £20,000 from April 2028.

Quarterly updates for standard periods are due 7 August, 7 November, 7 February and 7 May. Always confirm current dates on GOV.UK.

Track these automatically

Remindoo imports Companies House dates and schedules every recurring deadline per client, with automated reminders to collect records.

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Frequently asked questions

When is the Self Assessment deadline?

Online returns and balancing payments are due by 31 January following the end of the tax year.

When are company accounts due at Companies House?

For private companies, 9 months after the accounting reference date (except for the first accounts, which have different rules).

Waqas Sagar

Chartered accountant and Remindoo co-founder · Last updated 24 September 2026

Built for UK practice growth

Every deadline. Every client. One system.

Start with the workflows that cause the most chasing, then bring leads, AML, proposals and clients into the same calm operating system.

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Why recording every task matters in an accountancy practice

Accounting firms run on deadlines: VAT returns, payroll, confirmation statements, accounts and Self Assessment. Recording every job as a task, with an owner and a date, is the simplest way to make sure nothing is missed.

Avoid penalties

HMRC and Companies House charge penalties for late filing. A task for every deadline, with an internal date before it, gives the team a buffer.

Nothing depends on memory

Recorded tasks mean work continues when someone is off sick, on leave or has left the firm.

Consistent quality

Subtask checklists make every job follow the same steps and reviews, whoever does the work.

Visibility for managers

Filters by owner, status and deadline show at a glance what is late, what is due and who needs help.

Practical tips from UK practice

Set an internal deadline two to four weeks before every statutory deadline.
Use recurring tasks for repeat work such as VAT, payroll and bookkeeping.
Break larger jobs into subtasks, including a review step.
Comment on the task instead of by email, so the history stays with the work.

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Written and reviewed by Waqas Sagar ACA FCCA FMAAT, Chartered Accountant with 18+ years in practice. Founder and MD of Accotax, an ICAEW, ACCA and AAT regulated London practice that has served over 5,000 clients, and founder of Remindoo. Guidance is general; check current GOV.UK and professional body guidance for your firm.

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