Running a small business in the UK means keeping track of more than sales, customers and cash flow. You also need to know when HM Revenue & Customs (HMRC) expects returns, reports and tax payments. The challenge is that there is no single HMRC deadline for every business. Your obligations depend on how your business is structured and which taxes or schemes apply to you.

A limited company may need to manage Corporation Tax, VAT and PAYE, while a sole trader may primarily deal with Self Assessment and possibly VAT. An employer may also have annual reporting obligations for employee benefits. This guide provides a practical HMRC tax calendar for small businesses, explains the most important deadlines and shows how to build a system that reduces the risk of late filing penalties, interest and unnecessary stress.

Important: HMRC deadlines can depend on your accounting period, VAT scheme, payroll frequency and individual circumstances. Always check the specific deadline shown in your HMRC account or official correspondence before making a payment.

HMRC Tax Calendar at a Glance

Here are some of the most common deadlines small businesses need to understand:

These are typical dates, not a substitute for checking your business's actual deadlines. Different accounting periods and tax arrangements can change the date.

Understanding the UK Tax Year

Before building a tax calendar, it helps to understand the UK tax year. The tax year for individuals runs from 6 April to 5 April the following year. For example:

• 2025/26 tax year: 6 April 2025 to 5 April 2026
• 2026/27 tax year: 6 April 2026 to 5 April 2027

This is particularly important for sole traders and directors who have personal Self Assessment obligations. A limited company's Corporation Tax accounting period is different. It normally follows the company's accounting period and does not necessarily coincide with the UK tax year. That distinction is one of the most common sources of confusion for new business owners.

January: A Major HMRC Deadline Month

January is one of the busiest months in the small-business tax calendar.

31 January — Self Assessment deadline

If you are required to file an online Self Assessment tax return for the previous tax year, the usual filing deadline is 31 January. The same date is generally the deadline for paying:

• Any remaining tax from the previous tax year
• Your first payment on account for the current tax year, if payments on account apply

For example, the 2024/25 Self Assessment tax return is generally due online by 31 January 2026.

Who might need to file?

Depending on their circumstances, this can include:

• Sole traders
• Partners in partnerships
• Company directors
• Landlords
• Individuals with certain additional income
• People with other taxable income requiring Self Assessment

Not every company director automatically has to file a Self Assessment return, so the obligation should be considered based on the individual's circumstances.

July: The Second Self Assessment Payment on Account

31 July — Second payment on account

If you are required to make payments on account, the second instalment is normally due on 31 July. Payments on account are advance payments towards your next Self Assessment bill. They are generally based on your previous year's tax liability, subject to the rules and exceptions that apply. This can create a significant cash-flow issue for growing businesses.

Example

Suppose a sole trader has a Self Assessment liability of £8,000 and payments on account apply.

They may need to make:

• £4,000 by 31 January
• £4,000 by 31 July

The following January may then include the balancing payment for the new tax year as well as another payment on account. This is why a business owner can face a surprisingly large January tax bill even when the business has not suddenly generated an enormous profit.

Corporation Tax Deadlines for Limited Companies

Corporation Tax deadlines are based on the company's Corporation Tax accounting period, not simply the calendar year. For most companies with taxable profits of up to £1.5 million, Corporation Tax is normally due 9 months and 1 day after the end of the accounting period. The Company Tax Return itself normally has a separate deadline: 12 months after the end of the accounting period. That means you can have a situation where:

• Corporation Tax must be paid first
• The Company Tax Return is filed later

This catches inexperienced directors out.

Example

Imagine a company has a Corporation Tax accounting period ending on 31 March 2026. Its Corporation Tax payment would normally be due on:1 January 2027, Its Company Tax Return would normally be due on: 31 March 2027,The tax payment and tax return therefore have different deadlines.

Companies House Accounts Are Another Deadline

Although Companies House is separate from HMRC, small company owners should put Companies House deadlines on the same calendar. A private limited company's annual accounts are generally due 9 months after the end of its financial year.

This is separate from the Corporation Tax return. For a company with a 31 March year-end, for example, the annual accounts deadline would generally be 31 December, while Corporation Tax would usually be payable on 1 January and the Company Tax Return would generally be due the following 31 March. That creates a useful three-date checklist:

Accounts → Corporation Tax payment → Company Tax Return

Do not treat them as one filing obligation.

VAT Deadlines

If your business is VAT registered, VAT becomes a recurring part of your tax calendar. For businesses using the standard VAT accounting cycle, VAT Returns are usually submitted every three months. The standard online deadline is generally one calendar month and seven days after the end of the VAT accounting period, and payment must reach HMRC by the deadline.

Example

If your VAT quarter ends on: 31 March, your usual online VAT Return and payment deadline would be:7 May, If the quarter ends on 30 June, the deadline would normally be 7 August. However, businesses using Annual Accounting or other VAT arrangements can have different deadlines. Your VAT online account should be treated as the definitive source for your specific VAT dates.

VAT Returns Still Matter Even If You Owe Nothing

One useful point for new businesses is that being required to submit a VAT Return does not depend on whether you have VAT to pay. A VAT-registered business generally needs to submit its return even where the return shows no VAT payable or a repayment. So a quiet quarter does not necessarily mean you can ignore your VAT obligations. A "nil" VAT period still requires attention.

PAYE Deadlines for Employers

If your company employs people, PAYE adds another recurring deadline. Employers generally report payroll information to HMRC through payroll submissions and pay the amount due from deductions and employer liabilities. When paying electronically, PAYE is generally due by the 22nd of the following tax month. If paying by cheque through the post, the payment normally needs to reach HMRC by the 19th.

Example

If your payroll tax month ends on 5 September, your PAYE payment would generally be due by: 22 September, For businesses that qualify to pay PAYE quarterly because their average monthly PAYE liability is low, different payment arrangements may apply.

What If You Pay Employees but Have No PAYE to Pay?

This is another area where employers can make mistakes. If you have not paid any employees for an entire tax month, you may need to tell HMRC by submitting an Employer Payment Summary (EPS). HMRC states that an EPS should generally be submitted by the 19th of the month following the tax month in which no employees were paid. Simply assuming "there is nothing to pay, so there is nothing to report" can therefore be risky.

July Employer Deadlines: P11D and Benefits

Businesses providing benefits or expenses to employees may have additional annual reporting requirements. The typical deadline for reporting expenses and benefits is: 6 July following the end of the tax year. Where applicable, Class 1A National Insurance is generally payable by: 22 July when paying electronically. This can apply to benefits such as:

• Company cars
• Private medical insurance
• Certain employee benefits
• Other taxable benefits provided by an employer

Not every small business has P11D obligations, but employers should check rather than assume.

October: PAYE Settlement Agreement Payment

A PAYE Settlement Agreement (PSA) allows an employer to settle certain tax and National Insurance liabilities on specific expenses and benefits. Where a PSA applies, payment is generally due by: 22 October when paying electronically. The deadline is 19 October when paying by cheque. The application deadline is generally 5 July following the end of the tax year to which the PSA relates.

A Practical HMRC Calendar for Small Businesses

Rather than memorising dozens of dates, build your calendar around recurring cycles.

Every month

Check:

• PAYE liability
• Payroll submissions
• VAT cash reserve
• HMRC online account
• Upcoming tax payments
• Bank balance against expected liabilities

Every quarter

Review:

• VAT Return deadline
• VAT payment
• Payroll liabilities
• Management accounts
• Corporation Tax provision
• Cash flow forecast

Every six months

For businesses with Self Assessment obligations:

• Check January tax position
• Check July payment-on-account position
• Reforecast expected personal tax

Annually

Review:

• Companies House accounts
• Company Tax Return
• Corporation Tax
• Self Assessment
• P11D requirements
• Class 1A National Insurance
• PAYE Settlement Agreement requirements
• VAT registration status
• Tax registrations and business details

How to Build a Tax Calendar That Actually Works

A tax calendar should not simply contain deadlines. It should tell you when to start preparing. For example, if your Corporation Tax payment is due on 1 January, don't put "pay Corporation Tax" on your calendar for 1 January and forget about it. Instead, create several internal dates:

8 weeks before

Estimate the liability.

4 weeks before

Review accounting records and cash reserves.

2 weeks before

Confirm the amount payable.

5 working days before

Schedule the payment.

Deadline day

Verify that the payment has been made or is scheduled correctly. This approach turns a deadline into a process.

Why Small Businesses Miss HMRC Deadlines

Late filing is often not caused by deliberate non-compliance. Common causes include:

Poor record keeping

The business cannot complete its return because invoices, receipts or bank information are missing.

Cash-flow problems

The owner knows the tax is due but does not have enough money available.

Confusing filing and payment deadlines

This is particularly common with Corporation Tax.

Ignoring HMRC letters

A business owner may miss a notice because correspondence is going to an old address.

Assuming an accountant handles everything

An accountant can manage tax work, but directors and business owners remain responsible for their company's obligations.

International founders missing UK correspondence

Overseas directors should have a reliable system for monitoring UK tax communications.

Tax Calendar Tips for Overseas Business Owners

A UK company can be owned or managed by people living outside the UK. For global founders, tax administration needs an extra layer of discipline. Keep a central record containing:

• Company UTR
• PAYE reference
• VAT number
• Companies House number
• Accounting period
• VAT quarters
• Payroll dates
• Corporation Tax deadline
• Company Tax Return deadline
• Companies House filing deadline
• Relevant Self Assessment deadlines

This is particularly valuable when the founder, accountant and company administration provider are in different countries. IncorpUK, for example, may be relevant to global founders using a UK company formation and management platform, but the business should still maintain its own master compliance calendar.

What Happens If You Miss an HMRC Deadline?

The consequences depend on the obligation. A late Corporation Tax payment can result in interest and potentially other consequences. Late Company Tax Returns can attract filing penalties even where no Corporation Tax is payable.

VAT has its own penalty regime. For VAT accounting periods beginning on or after 1 January 2023, late submissions can result in penalty points, with a financial penalty applying once the relevant threshold is reached. Late payment penalties are dealt with separately.

PAYE late payments can also result in interest and penalties. The practical lesson is simple: do not wait for a penalty notice before taking action. If you realise you have missed a deadline, deal with the problem immediately and establish what is now required.

The Best Way to Stay Ahead of HMRC

A strong compliance system has three layers.

Layer 1: Know the dates

Maintain a central calendar.

Layer 2: Prepare early

Set internal deadlines before HMRC's deadlines.

Layer 3: Keep money aside

Treat VAT, PAYE and Corporation Tax liabilities as money owed to HMRC rather than spare business cash. This last point is especially important. A business can appear profitable while simultaneously having a serious tax cash-flow problem. For example, VAT collected from customers is not simply additional revenue available to spend. A portion may ultimately need to be paid to HMRC.

HMRC Tax Calendar FAQs

What is the main tax deadline for a UK small business?

There is no single deadline. Depending on the business, important dates can include VAT, PAYE, Corporation Tax, Self Assessment and Companies House filing deadlines.

When is Corporation Tax due?

For most companies with taxable profits of up to £1.5 million, Corporation Tax is normally due 9 months and 1 day after the end of the Corporation Tax accounting period.

When is a Company Tax Return due?

Normally 12 months after the end of the Corporation Tax accounting period.

When is VAT due?

For most businesses using standard quarterly VAT accounting, the online VAT Return and payment are generally due one calendar month and seven days after the end of the accounting period.

When is PAYE due?

PAYE is generally due by the 22nd of the following tax month when paying electronically. Quarterly arrangements may apply to eligible employers.

When is Self Assessment due?

The online Self Assessment return and associated payment are generally due by 31 January following the end of the tax year. Additional payments on account may be due on 31 July and 31 January.

Does Companies House have the same deadlines as HMRC?

No. Companies House and HMRC have separate filing systems and deadlines. A company may need to file annual accounts with Companies House while separately filing a Company Tax Return with HMRC.

Do tax deadlines change for new companies?

They can. A company's first Corporation Tax accounting period can result in unusual or multiple filing and payment deadlines. HMRC notes that a first set of accounts may sometimes require two Corporation Tax returns because a Corporation Tax accounting period cannot exceed 12 months.

What should I do if I cannot pay HMRC on time?

Contact HMRC as soon as possible rather than ignoring the liability. Depending on the circumstances, you may be able to discuss payment arrangements, but interest and penalties can still apply.

Final Takeaway

A good HMRC tax calendar does more than remind you about filing dates. It gives you visibility over the financial obligations that can affect your business's cash flow, compliance and reputation. For most small businesses, the critical dates to monitor are:

• 31 January — Self Assessment
• 31 July — second Self Assessment payment on account, where applicable
• VAT deadline — usually one month and seven days after the VAT period ends
• PAYE — generally 22nd of the following tax month
• Corporation Tax — usually 9 months and 1 day after the accounting period
• Company Tax Return — usually 12 months after the accounting period
• Companies House accounts — usually 9 months after the financial year-end for private companies
• 6 July — P11D and benefits reporting, where applicable
• 22 July — Class 1A National Insurance, where applicable
• 22 October — PAYE Settlement Agreement payment, where applicable

The smartest approach is to put these dates into a calendar before they become urgent. Then work backwards, giving yourself enough time to prepare records, confirm figures and arrange payment. Tax compliance becomes much easier when it is treated as a routine business process rather than a last-minute administrative task. For small businesses and global founders alike, a well-maintained HMRC calendar can prevent avoidable penalties and, just as importantly, make tax liabilities much easier to plan for.