The 5 October Deadline: When Vinted, eBay and Etsy Sellers Must Tell HMRC

If you had gross income from selling on Vinted, eBay, Etsy or any other platform exceeding £1,000 in the 2025/26 tax year and are not already registered for Self Assessment, the deadline to tell HMRC is 5 October 2026. Missing this deadline means HMRC can look further back into your tax affairs and the penalties increase. Acting before the deadline, even if you are registering late for prior years too, gives you the best possible outcome.

Jade had been selling on Vinted for almost three years. She had watched the conversation drift into her Facebook group on a Thursday evening. Someone mentioned the 5 October deadline. Someone else explained what it meant. Jade read the thread twice, then put her phone down and stared at the wall for a moment.

She had never registered for Self Assessment. She had known, somewhere at the back of her mind, that she probably should have done something about her selling income by now. She just had not known what, or when, or how urgent it was.

The answer to all three of those questions is this post.

What If You Have Been Selling for More Than One Year Without Registering?

If you have been selling for more than one year without registering, you need to address all years where you had a tax liability, not just 2025/26. Registering for 2025/26 does not automatically resolve your position for 2023/24 and 2024/25. HMRC can look back up to four years for honest mistakes and up to twenty years for deliberate non-disclosure. eBay, Vinted and Etsy have been reporting seller data to HMRC since January 2025 under DAC7 rules.

Jade has been selling since 2023. She has a potential tax liability for three tax years. The 5 October 2026 deadline is the registration deadline for 2025/26 specifically. Her prior years, 2023/24 and 2024/25, are addressed through HMRC's voluntary disclosure process, which runs alongside the Self Assessment registration.

The most important thing Jade can do right now is come forward voluntarily before HMRC contacts her. The penalty for a voluntary unprompted disclosure to HMRC ranges from 0 percent to 100 percent of the tax owed. For careless mistakes, the penalty can often be reduced significantly or to zero. The key distinction is whether the failure was non-deliberate, which covers sellers who genuinely did not know they were required to register, and whether the disclosure is unprompted, meaning Jade contacts HMRC before they contact her.

Jade did not know she was trading in the legal sense. She did not know the 5 October deadline existed. Her failure to register is almost certainly non-deliberate. If she registers now and discloses her full position, the penalty on the late registration itself can potentially be nil. She will still owe the tax for each year plus interest on the late payment, but the penalty loading on top of the tax can be avoided if she acts before HMRC makes contact.

Our post on what happens when you register for Self Assessment late covers the process for prior years in detail.

What Happens If You Miss the 5 October Deadline?

Missing the 5 October deadline means your registration is late. The penalty for late registration is calculated as a percentage of the potential lost revenue, the tax you owed and did not declare, rather than a fixed amount. For a non-deliberate failure disclosed voluntarily before HMRC contacts you, the penalty can be reduced to zero, though you will still owe the underlying tax and interest. If HMRC contacts you first, the minimum penalty applies even for non-deliberate failures.

This is the commercial case for acting now rather than after 5 October. The difference between a voluntary unprompted disclosure and one that happens after HMRC sends a nudge letter is not just the penalty rate. HMRC can also look further back into your affairs once an enquiry is opened, which means more years of potential liability come into scope.

If you did not register for a Self Assessment tax return by the appropriate deadline, you will have to pay what you owe for up to twenty years. You will only have to pay for up to four years if you registered by the appropriate deadline and took care to make sure your tax affairs were right.

This is the most important number in this post. Register on time and HMRC looks back four years. Do not register and HMRC can look back twenty. Our penalties guide covers the full structure and our guide to appealing an HMRC penalty covers your options if a penalty is issued.

How Do You Register for Self Assessment Before 5 October?

Register for Self Assessment online through HMRC's Government Gateway at gov.uk/register-for-self-assessment. You will need a Government Gateway account, your National Insurance number, your contact details and the date you started self-employment or selling. Once registered, HMRC sends your Unique Taxpayer Reference by post within ten working days. You need this reference to complete your tax return. Allow enough time for it to arrive before the 31 January filing deadline.

The registration itself takes about twenty minutes if you have your National Insurance number to hand.

If you have income from prior years to declare, the voluntary disclosure process runs alongside the registration. The registered for Self Assessment late post covers how to address prior years at the same time.

What Happens After You Register?

After registering, you need to file your Self Assessment return for 2025/26 by 31 January 2027 and pay any tax owed by the same date. You will also need to address any prior years where you had a tax liability. The tax you owe is calculated on your trading profit, which is your gross income minus your allowable expenses. The higher your expenses relative to your gross income, the lower your taxable profit and the lower your tax bill.

This is also the point at which knowing your exact position matters most. Jade does not want to arrive at 31 January 2027 guessing what she owes. She wants to know in advance so she can save toward it throughout the autumn rather than scrambling for it in January.

Our guide to saving the right amount for your Self Assessment bill covers the set-aside percentages that work for different income levels, and our how much tax will I pay as a sole trader guide helps you estimate your bill before you file. The Vinted tax guide and eBay tax guide cover the specific income and expense calculations for each platform.

Jade's Complete Position for 2025/26

Jade earns £24,000 from her teaching assistant role. Her personal allowance of £12,570 is almost entirely used by her employment income before her selling income is considered. This means her trading profit from selling is taxable from the first pound, at the combined income tax and Class 4 National Insurance rate of approximately 26 percent.

Her gross income from selling in 2025/26 was £11,200. If she claims the trading allowance, her taxable profit is £10,200. At 26 percent, her tax bill on the selling income is approximately £2,652.

If she tracks and claims her actual expenses, packaging at £180, mileage at £420, her share of phone costs at £120, and stock purchased during the year at £2,800, her total actual expenses are £3,520. Her taxable profit under actual expenses is £7,680, and her tax bill drops to approximately £1,997.

The difference between the two approaches is approximately £655. Claiming actual expenses is significantly better for Jade at her income level. But she can only access that calculation if she has kept records. Which is exactly why registering and starting to track properly now, rather than waiting, makes a real financial difference.

The UK Online Seller Tax Template calculates Jade's exact position including the interaction between her teaching assistant salary and her selling income, shows her what to set aside from every Vinted and eBay payment, and produces the exact figures her Self Assessment return needs.

Get the UK Online Seller Tax Template, £14.99 per year →

What Is the 5 October Self Assessment Deadline?

The 5 October deadline is the date by which you must notify HMRC that you need to complete a Self Assessment tax return for the previous tax year. For the 2025/26 tax year, which ended on 5 April 2026, the notification deadline is 5 October 2026. This is separate from the filing deadline of 31 January 2027 and the payment deadline of 31 January 2027. The 5 October date is about telling HMRC you exist as a taxpayer who needs to file, not about filing the return itself.

HMRC uses this notification to send you a Unique Taxpayer Reference number and activate your Self Assessment account. Without that account, you cannot file your return online. Without the UTR, which can take two weeks or more to arrive by post, you cannot complete the registration process. This is why the deadline matters even though you have until January to file. Start the process too late in October and the UTR may not arrive in time to file by the January deadline.

Does the 5 October 2026 Deadline Apply to You?

The 5 October deadline applies to you if your gross trading income from all self-employment and selling activity exceeded £1,000 in the 2025/26 tax year, you were not already registered for Self Assessment, and you have a tax liability to declare. If your gross income was under £1,000, the £1,000 trading allowance covers it entirely and you do not need to register.

The question most sellers ask is: does this apply to me specifically? The answer depends on two things. What your gross income was, and whether you are trading or disposing of personal possessions.

If you bought items specifically to resell for profit, you are almost certainly trading. Our badges of trade guide covers the HMRC test in detail and our is my online selling a business quiz gives you a result for your specific situation in about three minutes.

Jade's position is clear. She sold £8,600 on Vinted and £2,600 on eBay in 2025/26, a combined gross income of £11,200. She has been buying stock from charity shops and car boot sales specifically to resell it. She is trading. The 5 October deadline applies to her.

What Counts as Gross Income for the 5 October Deadline?

Gross income for Self Assessment purposes means the full amount buyers paid for your items before any platform fees or costs were deducted. It is not the amount that arrived in your bank account. On eBay and Etsy, platform fees are deducted before payout, so your bank receipts are lower than your gross income. On Vinted, there are no seller fees, so your gross income matches your payout exactly.

This distinction matters because the £1,000 threshold that determines whether you need to register is based on gross income, not net receipts. A seller who received £950 in their bank account after eBay fees may have had gross income of £1,100 or more, which puts them above the threshold even though their bank statement suggests otherwise.

Our guides to finding your gross sales on Vinted and finding your gross sales on eBay show you exactly where to find the correct figure on each platform.