Key UK Tax Deadlines Every Business Needs to Know
An evergreen guide for sole traders, limited companies, freelancers, online sellers, and growing UK businesses.
Whether you run a limited company, operate as a sole trader, or earn income through side-hustles such as Vinted, Depop, Etsy or eBay, staying on top of key tax deadlines is essential.
Missing a deadline can lead to penalties, interest charges, and HMRC enquiries, all of which can be avoided with a clear understanding of what’s due and when.
This guide breaks down the core UK tax and accounting deadlines that apply every year, regardless of your business type or financial year-end.
Self-Assessment (Sole Traders, Directors & Online Sellers)
Self-Assessment applies to:
- Sole traders
- Company directors
- Landlords
- Freelancers
- Online sellers on platforms like Vinted, Depop, Etsy, eBay, Amazon, TikTok Shop, etc.
- Side-hustlers earning more than £1,000 per year
31 January
Deadline for:
- Filing your online Self-Assessment tax return
- Paying your balancing payment
- Paying your first payment on account (if applicable)
This date applies every year, and HMRC charges penalties from the moment you miss it.
31 July
Your second payment on account is due (if applicable).
5 October
Deadline to register for Self-Assessment if you became self-employed or started earning untaxed income in the previous tax year.
Important for small sellers:
If you make more than £1,000 profit in a year from Vinted, Depop, eBay or similar platforms, you must register for Self-Assessment.
Corporation Tax (Limited Companies)
Regardless of when your financial year ends, these deadlines stay the same:
12 Months After Year-End
Deadline to file your Company Tax Return (CT600) with HMRC.
9 Months + 1 Day After Year-End
Deadline to pay your Corporation Tax.
Example:
If your year-end is 30 June, Corporation Tax is due 1 April the following year.
Even if your company is not trading, you must still meet filing requirements unless formally dormant with HMRC and Companies House.
VAT (Quarterly or Monthly Registered Businesses)
VAT deadlines depend on your reporting cycle, but the rule stays the same:
1 Month + 7 Days After VAT Period Ends
Your VAT return and payment are due.
This applies whether you file monthly, quarterly, or annually.
Typical mistake:
Mixing up the VAT return deadline with the payment deadline, they are the same.
PAYE (Payroll), National Insurance & Pensions
By the 22nd of Each Month
PAYE and National Insurance must be paid (19th if paying by post).
On or Before Payday
Your RTI (Real Time Information) submission must be filed every time you pay staff.
By 31 May
Provide P60 certificates to employees.
By 6 July
Submit P11D forms for employee benefits.
By 22 July
Pay Class 1A NIC (19th if posting a cheque).
Including online sellers?
Yes — if you start hiring part-time help, even casually, payroll obligations may apply.
Companies House Annual Requirements (Limited Companies)
Annual Accounts
Must be filed 9 months after your accounting year-end.
Confirmation Statement
Due every 12 months, usually within 14 days of the statement date.
This applies even if you:
- haven’t traded
- made a loss
- have no employees
Failure to file can result in the company being struck off.
CIS (Construction Industry Scheme)
For contractors and subcontractors:
Monthly CIS Return
Must be submitted by the 19th of each month.
Payment of CIS deductions
Due by the 22nd (electronic) or 19th (post).
Auto-Enrolment Pension Obligations
Every Payroll Cycle
Pension contributions must be paid to the scheme provider.
Every 3 Years
Re-enrol eligible staff and complete the re-declaration of compliance.
Even small businesses with fewer than 5 staff must comply.
Business Rates
Local councils set the instalment plan, but most businesses pay:
- Monthly instalments (April–January)
or - In full at the start of the year
Deadlines vary by council but are consistent annually.
Import & Export Duties
Deadlines depend on:
- Deferment accounts
- VAT postponed accounting
- Customs declarations
- Freight Provider Terms
Businesses importing goods for resale, including online sellers, must stay aware of their specific duty payment timings.
Staying Compliant Means Staying Ahead
These deadlines recur every year, and while they may feel overwhelming, a simple structured system or professional support makes compliance straightforward.
PG Owen & Accounting Services can help you:
- Track and meet all filing deadlines
- Avoid penalties and late fees
- Improve cash flow through smarter tax planning
- Manage Self-Assessment, VAT, payroll, CIS, and Corporation Tax
- Stay compliant whether you're a limited company or a small Vinted/Depop seller
Contact us to speak to one of our expert advisors.