UK Online Business Tax Rules: Registration, VAT & Deadlines

Selling through Shopify, Amazon, Etsy or TikTok does not create a separate UK tax system. Your obligations depend on whether you are trading, your business structure, taxable turnover and where goods or customers are located. A marketplace reporting your sales to HMRC is not the same as paying your taxes for you.

Are you trading or selling personal possessions?

Buying goods to resell or making products for sale is likely to be trading. Clearing out your own unwanted belongings is different, although separate Capital Gains Tax rules can apply to valuable items. The number of listings alone does not settle the question. Use HMRC’s online-platform income guidance to assess the activity.

Sole traders: when to register for Self Assessment

If gross trading income exceeds £1,000 in a tax year, you normally need to register for Self Assessment. Consider all your trades together, not each shop separately. Exceptions can also require a return below that amount, and you must respond if HMRC asks you to file. The £1,000 allowance concerns gross income, not profit or the amount left after marketplace fees. See HMRC’s trading allowance rules.

Where you need to notify HMRC, the usual deadline is 5 October after the end of the relevant tax year. There is no general requirement to register for Self Assessment within three months of your first sale. Follow HMRC’s registration steps, including if you have filed before but need to register a new self-employment.

Self Assessment dates for the 2025/26 tax year

Payments on account can make the first substantial bill larger than expected. Different filing dates can apply if HMRC sends a later notice to file. Check the notice and HMRC’s Self Assessment deadlines; an extended filing date does not automatically extend the payment deadline.

Limited companies have separate filing obligations

A company accounts for its own profits and Corporation Tax. A director’s personal return is a separate question, depending on personal income and circumstances. Salary, dividends and loans cannot be treated interchangeably. See taking money out of a limited company.

For an established private company, annual accounts are normally due at Companies House nine months after its financial year end; first accounts have a different deadline. Corporation Tax payment is usually due nine months and one day after the accounting period ends, and the Company Tax Return is due after 12 months. Larger companies can have different payment rules. Check company accounts and tax-return deadlines.

VAT: monitor taxable turnover across all your channels

For a UK-established business, compulsory VAT registration normally applies when taxable turnover exceeds £90,000 over a rolling 12 months, or is expected to exceed £90,000 in the next 30 days alone. It is not a profit threshold or a test performed only at year end. Include the relevant sales of the same business across all platforms. Separate rules apply to non-established businesses. See HMRC’s VAT registration guidance.

Illustration: £55,000 of taxable Shopify sales plus £40,000 of taxable Etsy sales in the same rolling 12 months gives £95,000 for one business. Do not test each shop separately or reduce sales by platform fees to assess the threshold. Registration timing and the effective date depend on which test is met.

Overseas sales and marketplace tax collection

Check the seller’s establishment, goods location, customer status and whether the sale is direct or through a marketplace. A platform collecting tax on one type of order does not settle every obligation. Import VAT, UK VAT, EU schemes and local registrations answer different questions. Start with HMRC’s marketplace and direct-sales guidance.

Keep order-level tax and shipping records. If you hold stock overseas, sell digital products or dropship from a supplier, get the supply chain assessed before applying a blanket VAT rule. Our cross-border VAT guide and ecommerce tax and VAT service cover the questions to raise.

Making Tax Digital is not one rule for every business

MTD for Income Tax is separate from MTD for VAT. From 6 April 2026, eligible sole traders and landlords with qualifying income over £50,000 based on their 2024/25 return must use MTD for Income Tax, unless exempt. Qualifying income is assessed before expenses and can combine self-employment and property income. Check HMRC’s eligibility and start-date guidance.

Do not assume this applies to a limited company in the same way, or that quarterly updates replace the annual tax calculation and payment obligations. VAT-registered businesses should separately check keeping VAT records digitally.

Build a monthly record routine

• Export sales, refunds, fee invoices and settlement reports from every platform.
• Reconcile gross sales and deductions to bank deposits; investigate reserves and timing differences.
• Record stock, expenses and the business share of mixed-use costs.
• Update the rolling VAT-turnover check and set aside cash for tax and any payments on account.

Read allowable expenses for UK online sellers for deductions. If you need help organising the monthly records or preparing a return, see monthly ecommerce bookkeeping and pricing and scope.