If you sell on Amazon, Shopify, eBay, Etsy or TikTok Shop, HMRC now has far more visibility into your sales than most sellers realise. Since January 2024, online marketplaces have been legally required to report seller data directly to HMRC under new digital platform reporting rules, and HMRC has been using that data, alongside its own risk profiling systems, to open compliance checks and tax investigations into ecommerce sellers it believes have not declared income correctly.
This guide explains how HMRC tax investigations for ecommerce sellers actually work, what triggers a compliance check, how the rules differ between a marketplace like Amazon, eBay, Etsy or TikTok Shop and an independent Shopify store, and what to do if HMRC has already been in touch. If you are still working out whether your online selling counts as a taxable trade in the first place, our guide to tax on online sales in the UK is the right place to start before reading on.
Table of Contents
- Why Ecommerce Sellers Are Under More HMRC Scrutiny Than Ever
- How HMRC Now Receives Data From Amazon, eBay, Etsy and TikTok Shop
- Does This Apply to Shopify and Independent Website Sales Too
- What Triggers an HMRC Compliance Check for Ecommerce Sellers
- Nudge Letters, Compliance Checks and Formal Investigations Explained
- Penalties for Undeclared Ecommerce Income
- How Far Back Can HMRC Investigate an Ecommerce Business
- How to Get Compliant Before HMRC Contacts You
- What to Do If HMRC Has Already Been in Touch
- How an Ecommerce Accountant Can Help
- Staying Ahead of HMRC as an Ecommerce Seller
Why Ecommerce Sellers Are Under More HMRC Scrutiny Than Ever
Online selling has grown enormously over the past few years, and HMRC’s ability to check who is earning what has grown just as quickly. For a long time, sellers on Amazon, eBay, Etsy and similar platforms could reasonably assume that HMRC only saw what appeared on a tax return. That assumption no longer holds.
HMRC now combines platform reporting with its own data matching systems to build a much clearer picture of who is trading online, how much they are earning, and whether that matches what has been declared. This has led to a noticeable increase in one to many letters, informal nudges and formal compliance checks aimed specifically at online sellers, including many who have been quietly trading for years without ever registering with HMRC.
None of this means ecommerce selling has become riskier as a business model. It simply means the accounting and tax side needs to be treated with the same seriousness as the buying, listing and fulfilment side, which is exactly where our ecommerce accountants service is designed to help.
How HMRC Now Receives Data From Amazon, eBay, Etsy and TikTok Shop
Under the UK’s digital platform reporting rules, which came into force on 1 January 2024, online marketplaces that connect sellers to buyers are required to collect information about their sellers and report it to HMRC once a year. The first reports, covering the 2024 calendar year, were due to HMRC by 31 January 2025, and platforms now continue to report every year on the same cycle.
The data shared typically includes the seller’s name, address and tax reference where held, bank account details used to receive payments, total income paid out during the year, and the number of transactions involved. Sellers who make a smaller number of occasional sales, generally fewer than 30 items and under roughly 2,000 euros in a calendar year, are usually excluded from reporting, but many active Amazon, eBay, Etsy and TikTok Shop sellers sit well above that line without realising it.
This is why some sellers who have not changed anything about how they trade are suddenly hearing from HMRC. The business has not changed, but HMRC’s ability to see it has. Keeping accurate, reconciled records that match what each platform reports is now one of the most important habits an ecommerce seller can build, which is exactly what good ecommerce bookkeeping is there to protect.
Does This Apply to Shopify and Independent Website Sales Too
Shopify works differently to Amazon, eBay, Etsy and TikTok Shop for the purposes of these specific reporting rules. Shopify provides the software behind an independent online store rather than acting as a marketplace that connects many sellers to buyers, so a typical Shopify store is not covered by the digital platform reporting rules in the same automatic way.
That does not mean Shopify sellers are outside HMRC’s reach. Payment processors such as Stripe, PayPal and card acquirers have their own reporting obligations, VAT returns and bank account activity remain fully visible to HMRC under existing powers, and HMRC’s risk profiling increasingly cross references turnover against lifestyle indicators, industry benchmarks and supplier data. A seller who trades across Shopify and a marketplace at the same time should assume HMRC can see the marketplace side directly and can still reach the Shopify side through other means.
The safest position for any seller, regardless of which platform they use, is accurate bookkeeping supported by proper ecommerce accounting software that reconciles sales, fees and refunds across every channel, so nothing depends on which platform happens to report and which does not.
What Triggers an HMRC Compliance Check for Ecommerce Sellers
There is rarely one single reason HMRC opens a check, but the following are the most common triggers behind HMRC tax investigations for ecommerce sellers that we see among Amazon, Shopify, eBay, Etsy and TikTok Shop sellers.
- A mismatch between the sales figures a marketplace reports to HMRC and the income declared on a self assessment return or through a limited company.
- Consistently low or nil declared profit alongside an active, ongoing seller account with regular listings and reviews.
- Turnover that has grown past the VAT registration threshold without a VAT registration ever being completed, which our VAT for ecommerce sellers guide covers in more detail.
- Bank deposits, stock purchases or advertising spend that look inconsistent with the profit being reported.
- Sector wide campaigns where HMRC focuses on a particular type of seller or platform for a period, often following the kind of accounting mistakes covered in our guide to common ecommerce accounting mistakes.
- Information that comes in from a third party, a related check into a supplier or platform, or simply random selection.
Most of these triggers have a common thread: the numbers HMRC can see from the outside do not match the numbers on the tax return.
Nudge Letters, Compliance Checks and Formal Investigations Explained
HMRC does not jump straight to a full investigation. There is usually a clear escalation path, and understanding where a letter sits on that path matters when deciding how to respond.
- One to many nudge letters are sent to groups of taxpayers HMRC believes may have undeclared income, based on data it holds. They are not an investigation, but they are also not something to ignore, since they usually invite a voluntary disclosure within a set number of days.
- An aspect compliance check looks at one specific part of a tax return or set of accounts, for example VAT on marketplace fees or the treatment of stock.
- A full compliance check reviews the entire tax position of the business or individual, usually involving an information notice requesting records, and sometimes a meeting with an HMRC officer.
- Where HMRC suspects deliberate and serious under declaration, cases can escalate to the Contractual Disclosure Facility or, in the most serious cases, a criminal investigation.
Every one of these stages has strict time limits for responding, which is why getting advice as soon as a letter arrives, rather than after a deadline has passed, makes a real difference to the outcome.
Penalties for Undeclared Ecommerce Income
Where HMRC finds tax has gone unpaid, penalties are calculated as a percentage of the tax lost, and the percentage depends on behaviour rather than on how the income was earned. Understanding these penalty bands matters because HMRC tax investigations for ecommerce sellers almost always come down to how much tax was lost and how it happened.
- Careless errors, where reasonable care was not taken but there was no intention to avoid tax, typically attract penalties of up to 30 percent of the tax due.
- Deliberate but not concealed under declaration typically attracts penalties of up to 70 percent.
- Deliberate and concealed under declaration, where records were altered or hidden, can attract penalties of up to 100 percent of the tax due.
Penalties are usually reduced, sometimes substantially, where a seller comes forward with an unprompted disclosure before HMRC opens a check, compared with waiting to be found. Interest also accrues on unpaid tax and unpaid penalties from the date they were originally due, so the total bill grows the longer an issue is left unresolved. Our specialist tax advice team regularly supports ecommerce sellers through this exact process.
How Far Back Can HMRC Investigate an Ecommerce Business
How far HMRC can go back also depends on behaviour rather than a single fixed rule.
- Four years for an innocent error, where reasonable care was taken but a mistake was still made.
- Six years where HMRC considers the error careless.
- Twenty years where HMRC considers the under declaration deliberate.
In practice, this means an ecommerce seller should keep clear, organised records covering sales, fees, refunds and stock for at least six years as standard practice, which lines up closely with the record keeping our statutory accounts and Making Tax Digital services already build into a seller’s annual process.
How to Get Compliant Before HMRC Contacts You
If you suspect your Amazon, Shopify, eBay, Etsy or TikTok Shop income has not been fully declared, the strongest position is almost always to act before HMRC does, rather than waiting to see whether a letter arrives.
- Pull sales, fee and refund data from every platform you sell on and compare it honestly against what has actually been declared to HMRC.
- Register for self assessment or, where appropriate, a limited company and payroll, if you have not already, using guidance such as our self assessment for ecommerce sellers guide.
- Check whether your turnover means you should already be VAT registered, since this is one of the most common and most costly gaps we find.
- Make a voluntary disclosure through HMRC’s digital disclosure service where past income has genuinely been missed, ideally with an accountant managing the correspondence on your behalf.
- Move onto proper bookkeeping and reconciled accounts going forward, so this situation cannot repeat itself.
Coming forward voluntarily, with professional support, is consistently the option that leads to lower penalties and a far less stressful process than waiting to be caught.
What to Do If HMRC Has Already Been in Touch
If a nudge letter or a formal information notice has already landed, a few principles apply regardless of how serious the check turns out to be, since the same rules apply across HMRC tax investigations for ecommerce sellers of every size.
- Do not ignore it. Deadlines in HMRC letters are real, and missing one can remove options that would otherwise have been available.
- Do not respond in detail, admit to errors, or send records over, before getting professional advice, since an unconsidered response can make a straightforward situation harder to resolve.
- Gather your records across every platform you sell on so you have a complete, accurate picture before anyone else does.
- Bring in an accountant experienced in HMRC negotiations early. Our CFO services and specialist tax advice teams regularly deal directly with HMRC on behalf of ecommerce clients, which takes the direct pressure off the seller.
How an Ecommerce Accountant Can Help
Staying ahead of HMRC tax investigations for ecommerce sellers is mostly about the basics being done properly and consistently: sales from every channel reconciled to the bank, VAT handled correctly, self assessment or corporation tax returns filed on time, and clean records kept for as long as HMRC could reasonably ask for them. Our guide on how to choose an ecommerce accountant explains what to look for if you are comparing options, and our year end accounts for ecommerce sellers guide shows how that annual process ties everything together.
At NS Accounting, we work with Amazon, Shopify, eBay, Etsy and TikTok Shop sellers, alongside influencers and content creators, to keep multi channel bookkeeping accurate, filings on time, and records ready for HMRC scrutiny well before it ever becomes a problem. If HMRC has already contacted you, or you simply want a health check on where you stand, you can contact our team or book a free consultation in confidence.
Staying Ahead of HMRC Tax Investigations for Ecommerce Sellers
HMRC tax investigations for ecommerce sellers are becoming more common simply because HMRC can now see more than it ever could before. That is not a reason to panic, but it is a strong reason to make sure your bookkeeping, VAT position and tax returns genuinely reflect what your Amazon, Shopify, eBay, Etsy or TikTok Shop business actually earns.
If you would like a second opinion on your current position, help responding to an HMRC letter, or support putting accurate, HMRC ready records in place going forward, our team at NS Accounting specialises in exactly this kind of ecommerce compliance work. Get in touch or book a free consultation to talk it through.
