SME Compliance Calendar 2025-26: A Month-By-Month Guide To UK Business Obligations

Running a business comes with its fair share of pressure, but the biggest stress often comes from missed deadlines. A forgotten VAT submission, a late payroll filing, or an overlooked accounts deadline can quickly escalate into penalties that nobody wants to face. That is exactly why having a clear, practical and straightforward SME compliance calendar for 2025 to 2026 can make your year significantly smoother and far more predictable.

This guide breaks down the significant statutory obligations small businesses typically face in the UK. It is to help you prepare early, plan smarter and avoid any last-minute rush.

Adams Accountancy combines more than 50 years of experience with the latest accounting software to help SMEs stay on top of their compliance with ease. We look after everything, from bookkeeping and management accounts to payroll, PAYE and CIS, giving you complete peace of mind and more time to focus on growing your business.

If you need support managing your filing responsibilities, tax planning or year-end accounts, you can always reach out to us at Adams Accountancy. Call us on 01322 250 001 or email info@adams-accountancy.co.uk for tailored advice.

Why Start-Ups Need a Compliance Roadmap From Day One

For many start-ups, compliance becomes overwhelming because each obligation sits on a different timetable. Payroll is monthly, VAT can fall quarterly, year-end accounts depend on your incorporation date, and HMRC submissions vary by tax. Instead of treating these tasks as isolated admin jobs, it helps to approach them as part of an annual flow.

Below is a quick warm-up before we break the year down month by month. These are the core compliance responsibilities most SMEs must keep track of:

1. Payroll And PAYE Submissions

Every month, employers must run payroll accurately, issue payslips and submit Full Payment Submissions to HMRC. Any mistake or late filing can lead to real-time penalties, so consistent scheduling is essential.

2. VAT Returns

Most VAT-registered businesses file quarterly returns. The exact months depend on your stagger group, so SMEs should always map their quarters clearly at the start of the year.

3. Corporation Tax And Annual Accounts

Limited companies need to prepare statutory accounts, file them with Companies House, and submit a Corporation Tax Return to HMRC. The deadlines are usually 9 months after the financial year-end for accounts and 12 months for the tax return.

4. Self Assessment

Directors, partners and some employees often need to complete a Self-Assessment tax return. Even if the company is compliant, personal filing must not be overlooked.

Once you understand these recurring elements, the SME compliance calendar becomes much easier to follow. Now, let us move into the clear, practical month-by-month guide.

Your Complete SME Compliance Calendar for 2025-26

The following breakdown covers the most common submission dates, reminders and action points for UK SMEs. Your specific deadlines may vary based on VAT quarters, payroll dates and incorporation, but this provides a reliable structure for planning.

1. April 2025: Start Of The New Tax Year

• Update employee tax codes.
• Confirm any changes to National Minimum Wage rates.
• Review allowances for the new tax year and adjust payroll systems.
• Prepare for the first quarter of VAT  if your cycle begins in April.

2. May 2025: Early Year Planning

• Submit the previous year’s final payroll adjustments if required.
• Review any P60s issued in April.
• Prepare accounts if your year-end falls in winter or early spring.

3. June 2025: Mid-Quarter Compliance Checks

• Many SMEs have a VAT quarter ending this month.
• Begin collecting bookkeeping records  early to avoid last-minute pressure.
• Review employee benefits if you need to prepare P11D forms.

4. July 2025: P11D And Class 1A NI Deadlines

• Submit P11D forms for employee benefits.
• Pay Class 1A National Insurance by 19 July.
• Finalise VAT submissions for April to June staggers.
• Review bookkeeping for the first half of the tax year.

5. August 2025: Summer Compliance Review

• A quieter month for statutory deadlines, making it ideal for internal audits.
• Check Companies House deadlines for annual accounts.
• Prepare for upcoming quarterly VAT filings if your staggered end is in September.

6. September 2025: Quarter-End VAT And Filing Prep

• Gather all invoices and receipts to prepare your VAT return.
• Review cash flow in line with expected tax liabilities.
• Check deadlines for Corporation Tax if your year-end falls in December.

7. October 2025: Self Assessment Paper Deadline

• Paper Self Assessment returns must be submitted by 31 October.
• Continue with VAT returns as scheduled.
• Begin planning year-end payroll and holiday pay accruals.

8. November 2025: Accounts Preparation Season

• A strong month for preparing annual accounts due early in the new year.
• Review director expenses ahead of Self Assessment.
• Run a PAYE audit to correct any payroll discrepancies.

9. December 2025: Year-End Accounting Checks

• Confirm Christmas payroll dates in advance.
• Many companies have a financial year-end this month.
• Reconcile all bookkeeping to avoid a backlog in January.

10. January 2026: Self Assessment Deadline Month

• Submit Self Assessment tax returns by 31 January.
• Pay personal tax liabilities by the same deadline.
• Prepare for upcoming VAT submissions if your quarter ended in December.

11. February 2026: Post Deadline Review

• Review payroll software and rates for April changes.
• Start drafting accounts due in early spring.
• Check Companies House reminders for annual confirmation statements.

12. March 2026: Final Month Of The Tax Year

• Complete any planned tax planning actions before 5 April.
• Prepare for April payroll updates.
• Gather documents for year-end reporting and accounts preparation.

Stay Compliant And Confident With Adams Accountancy

Managing your compliance obligations doesn’t have to consume your valuable time or cause endless worry. At Adams Accountancy, we’ve spent over 50 years helping SMEs, local businesses, and individuals with the complexities of UK tax and regulatory requirements. As Institute of Chartered Accountants in England and Wales (ICAEW) qualified chartered accountants, we combine deep expertise with modern technology to keep your business compliant while you focus on what you do best.

Our flexible approach means we provide precisely the level of support you need, whether that’s comprehensive accounts preparation, specialist VAT guidance, complete payroll services, or strategic tax planning.

If you want personalised support for your 2025–26 compliance planning, contact us today on 01322 250 001 or email info@adams-accountancy.co.uk to get started.