Selling online is marvellous until the tax side of things catches up with you. And it always does.
Many e-commerce businesses face similar tax and compliance challenges as they expand. Things grow quickly, the focus stays on sales and fulfilment, and the tax stuff gets pushed to the back burner. Then one day there’s a VAT bill that wasn’t expected, or an accountant points out that thousands of pounds in expenses were never claimed. It’s a frustrating position to be in, especially when a bit of planning earlier on would have changed things considerably.
This blog covers the mistakes we see most often, and the genuine opportunities that many online sellers are sitting on without knowing it.
The tax picture for e-commerce is more complicated than most people expect
A local shop sells to people nearby, holds stock in one place, and deals with a fairly predictable set of obligations each year. E-commerce is rarely that tidy.
You might be selling across Amazon, Shopify, eBay, and Etsy at the same time. You could be importing stock from China or the US, dropshipping from a supplier, or using a fulfilment centre in another country. Each of those arrangements brings its own tax considerations. Stack them together and things get complicated fast.
That’s precisely why leaving your tax planning until the end of the year is potentially, such a costly habit.
The mistakes that we keep seeing
1. Missing the VAT registration threshold
In the UK, you’re required to register for VAT once your taxable turnover passes £90,000 in any rolling 12-month period. E-commerce businesses can grow quickly enough that this sneaks up on them, and by the time someone notices, there’s backdated VAT to pay, potential penalties, and a cash flow headache.
What makes it trickier is that VAT isn’t one-size-fits-all. Some products are standard-rated at 20%, others are zero-rated, and some are exempt entirely. Charging the wrong rate, or failing to charge VAT at all when you should be, creates real problems with HMRC down the line.
2. Cross-border VAT after Brexit
This one catches a lot of UK sellers off guard. If you’re selling into EU countries, you can’t simply treat those sales the way you did before 2021.
Businesses selling goods to customers in the EU should review their VAT obligations carefully, as registration and reporting requirements may vary depending on factors such as where goods are stored, how they are supplied, and the countries involved.
Many UK e-commerce businesses selling into Europe either don’t know this or haven’t done anything about it.
3. Sloppy ‘cost of goods’ tracking
Your taxable profit is calculated on what’s left after your costs. But if you’re not accurately tracking what you paid for your stock, your profit on paper could be higher than it should be, and you’re handing over more tax than necessary. This is especially common for businesses buying from overseas suppliers where invoices, shipping costs, duties, and exchange rates all need pulling together properly.
4. Forgetting about platform and processing fees
Amazon’s fees, PayPal charges, Shopify subscriptions, Royal Mail accounts, packaging. These all reduce your taxable profit, but they’re only useful if you’re actually claiming them. A surprising number of online sellers don’t, largely because they’re not doing proper bookkeeping and are instead just glancing at their bank balance.
5. Mixing personal and business money
It’s incredibly common, particularly with businesses that started small, to run their business from their personal account. Using a personal account for business transactions doesn’t just make your bookkeeping messy; it increases the chance of missing expenses, and mixing personal and business transactions can make record-keeping more difficult and increase the risk of errors.
6. Not preparing for Making Tax Digital
MTD for Income Tax is being rolled out and will apply to sole traders with qualifying income from April 2026. If your e-commerce income puts you above the relevant threshold, you’ll need digital records and quarterly submissions. A lot of business owners haven’t heard of this yet, let alone made any preparations.
Where the real opportunities are
Reviewing your business structure
A lot of e-commerce businesses run as sole traders when incorporation as a limited company would actually save them money. It’s not the right call for everyone, but once profits reach a certain level, and depending on profit levels and individual circumstances, operating through a limited company may offer tax planning opportunities compared with trading as a sole trader.
Claiming every expense you're entitled to
There’s often more here than people realise. Legitimate claimable expenses for e-commerce businesses typically include:
- Packaging and postage
- Platform and marketplace fees
- Website hosting, domains, and software
- Equipment including laptops and cameras
- Marketing and paid advertising
- A proportion of home costs if you work from home
- Staff wages and subcontractor fees
Failing to identify and record allowable business expenses could result in paying more tax than necessary.
The Annual Investment Allowance
Bought equipment, shelving, vehicles, or machinery for your business? The Annual Investment Allowance lets you deduct the full cost of qualifying purchases from your profits in the same year, up to £1 million. The Annual Investment Allowance can provide significant tax relief on qualifying capital expenditure, subject to the applicable rules and limits.
R&D tax credits
Some e-commerce businesses may qualify for R&D tax relief where their activities meet HMRC’s eligibility requirements. If your business has built its own software, developed a bespoke system for inventory or pricing, or carried out work to genuinely improve a product or process, it’s worth having a conversation about whether a claim is possible.
Using pension contributions to reduce your tax bill
For limited company directors, employer pension contributions are a deductible business expense and they don’t attract National Insurance. Employer pension contributions can be a tax-efficient way for company directors to save for retirement while obtaining corporation tax relief, subject to the relevant rules and limits.
It's worth getting proper advice
Tax rules around e-commerce are changing more regularly than in most sectors. VAT thresholds, digital reporting obligations, cross-border rules, and reliefs all shift, and keeping pace with all of it while actually running a business is genuinely difficult.
At 3E’s Accountants, we work with online retailers across the UK on everything from day-to-day bookkeeping and VAT returns through to longer-term tax planning. If you want to make sure you’re not paying more than you should, or just want someone to sense-check where things stand, get in touch with our team for a no-obligation consultation.
