UK Online Seller Tax Template

The worry most online sellers are carrying

You have seen the headlines. HMRC can now see your sales. Platforms like Vinted and eBay report seller data directly to HMRC. The nudge letters are going out.

So now there is a quiet worry in the back of your mind. Am I supposed to be declaring this? How much would I even owe? What happens if I have got it wrong without realising?

The honest truth is that most online sellers genuinely do not know where they stand, and the information out there does not help. Some of it says you owe nothing. Some of it makes it sound like HMRC is coming for everyone. The £1,000 figure, the £1,700 figure, the 30 sales figure all get mixed up until none of it makes sense.

What you actually need is something that takes your real numbers and tells you, in plain terms, exactly where you stand. That is what this template does.

Why a spreadsheet, and not accounting software

Most accounting software is built for businesses turning over tens of thousands of pounds, and it charges a monthly subscription to match. For a side hustle making a few thousand pounds a year, paying £10 to £35 every month for software you barely use makes no sense.

You are also not legally required to use software yet. Making Tax Digital, which requires HMRC-approved software and quarterly filing, only applies once your income crosses £50,000. Below that, a spreadsheet is perfectly acceptable to HMRC and far better suited to how a side hustle actually works.

This template gives you everything a sub-£50,000 online seller genuinely needs. No subscription. No monthly fee. One payment, and it is yours.

When you do eventually cross £50,000, the template tells you, so you know exactly when it is time to move to software. Until then, you are not paying for something you do not need.

What makes this different from every other seller spreadsheet

Most online seller templates are bookkeeping spreadsheets. They tell you what you earned and organise your numbers. That is useful, but it stops at the exact point where your real question begins.

Other templates tell you what you earned. This one tells you what you owe.

This template includes a full UK tax calculation built in. Enter your sales and costs, and it works out your income tax, your Class 4 National Insurance, your student loan repayment if you have one, and your payment on account, all using confirmed 2026/27 rates. It is the difference between knowing your turnover and knowing your tax bill.

What the template does

Works out your true gross income. Platforms take their fees before they pay you, so the money landing in your bank is not your real income. The template handles this properly, so you see your true gross sales, which is the figure HMRC actually cares about. Every column header has a built-in reminder explaining exactly what to enter, so you never accidentally record the wrong figure.

Tells you if you need to register. The £1,000 trading allowance is the line that decides whether you need to register for Self Assessment at all. The template tracks your gross trading income against it and tells you clearly whether you are over or under.

Separates personal sales from trading. Clearing out your own wardrobe is not taxable. Buying or making things to sell is. The template lets you flag personal item sales so they are correctly excluded from your trading income and your tax calculation.

Handles the day job. If you sell alongside employed work, the template accounts for the salary you already pay tax on through your job, so your side hustle tax is calculated correctly on top. This is the detail that catches people out, and most templates ignore it completely. A side hustler with a £30,000 salary and £18,000 of selling profit owes significantly more than someone with no day job and £18,000 of selling profit, because the salary uses up the personal allowance first.

Calculates your full tax bill. Income tax, Class 4 National Insurance, student loan across all five UK plans, and payment on account, all worked out automatically from your numbers.

Shows what to set aside. The dashboard tells you what percentage of every sale to put away for tax, so the January bill is money you already have rather than a panic.

Warns you when you approach thresholds. The dashboard flags when your gross income crosses the £1,000 trading allowance and when your combined income approaches £50,000 for Making Tax Digital. You see the warning before the threshold matters, not after.

What is inside the template

The template has five tabs, each designed to do one job well.

Start Here. A plain English guide that walks you through everything, including where to find your gross sales figure on each platform, the critical difference between what the buyer pays for postage (which is your income) and what you pay to deliver the item (which is your cost), and how to set up the template in Google Sheets if you are using the shared link.

Sales and Costs. One row per sale. You enter the date, a description, the gross sale amount, the platform fees, your delivery cost, and the cost of the item if you bought it to resell. A personal item flag lets you exclude wardrobe clearouts and similar non-trading sales. The net profit for each sale is calculated automatically. Every column header has a hover comment explaining exactly what to enter, so there is no guesswork.

Expenses. Your general business running costs that are not tied to a single sale. Phone, broadband, software subscriptions, packaging supplies, office costs, use of home, mileage, bank fees, professional fees and marketing. A dropdown list of categories matches the Self Assessment return structure so the figures transfer directly when you file.

Tax Summary. Your complete tax position, calculated automatically from the Sales and Costs and Expenses tabs. Nothing to fill in here except three inputs: your PAYE salary if you have a day job, your student loan plan, and whether this is your first year of payment on account. Everything else is calculated for you. Income tax, Class 4 National Insurance, student loan repayment and payment on account, all using confirmed 2026/27 rates.

Dashboard. Your year at a glance. Gross sales, net profit, total tax bill, total due by 31 January, and the percentage to set aside from every sale. Threshold warnings for the £1,000 trading allowance and the £50,000 MTD threshold. All calculated automatically.

Built for how side hustles actually work

You do not need to import confusing CSV files or learn new software. You enter your sales into a simple sheet, one row per sale, with clear reminders at every column so you know exactly what goes where. It works the same whether you sell on one platform or five.

It works in both Google Sheets and Excel. If you live in Google Sheets on your laptop or phone, it works there. If you prefer Excel, it works there too. You are not locked into one.

And it is genuinely simple. If you can fill in a row of a spreadsheet, you can use this. The tax calculations happen on their own in the background.

The honest comparison

Most online seller templates cost between £10 and £25 and stop at bookkeeping. Monthly accounting software costs £120 to £420 per year. A bookkeeper costs £600 to £2,000 per year. This template costs £14.99 once, does the bookkeeping and the tax calculation, and requires no monthly commitment.

For sellers under £50,000 who are not yet required to use software, the maths is straightforward.

Who this is for

Online sellers and side hustlers earning under £50,000 who want to know their tax position without paying for monthly software.

People who sell on Vinted, eBay, Etsy, Depop, Amazon, Shopify or through PayPal and are not sure whether they owe tax or need to register.

Side hustlers with a day job who need their tax calculated correctly on top of their salary.

Anyone who has received an HMRC nudge letter, or is worried they might, and wants to get their position straight.

Who this is not for

Sellers earning over £50,000, who are required to use Making Tax Digital software for quarterly filing.

VAT-registered businesses, as this template does not handle VAT.

Limited companies, as this is built around sole trader tax.

Frequently asked questions

Do I really not need a subscription? No. For sellers under £50,000, a spreadsheet is perfectly acceptable to HMRC. Monthly software is only required once you cross £50,000 and fall under Making Tax Digital.

Does this work in Google Sheets? Yes. Upload it to your Google Drive, open it as a Google Sheet, and it works fully. It also works in Excel if you prefer. The Start Here guide explains how to get your own copy.

I sell on more than one platform. Does that matter? No. The template is platform-agnostic. Whether you sell on one platform or five, every sale goes into the same simple sheet.

I have a full-time job and sell on the side. Will it still work? Yes, and this is where it is genuinely better than most templates. It accounts for the tax you already pay through your job, so your side hustle tax is calculated correctly on top rather than being understated.

What if I am only selling my own old clothes? Then you almost certainly owe nothing, and the template will confirm that. You can flag personal item sales so they are excluded, and see clearly whether any of your activity counts as trading.

Will it tell me if I need to register with HMRC? Yes. It tracks your gross trading income against the £1,000 threshold and tells you plainly whether you need to register.

What about postage? How do I handle buyer-paid postage versus my delivery cost? The Start Here guide explains this clearly with worked examples, and every column header has a reminder. Postage the buyer pays you is part of your gross income and goes in the gross sale column. What you pay to send the item is your delivery cost and goes in the delivery cost column. The template handles both correctly.

What student loan plans are supported? All five UK plans. Plan 1, Plan 2, Plan 4, Plan 5 and the Postgraduate plan. If you have both an undergraduate and a postgraduate loan, the template handles the stacking correctly.

Is this tax advice? No. It produces accurate estimates based on the figures you enter and confirmed 2026/27 rates, but it is not personal tax advice. For complex situations, a qualified accountant is the right call.

The honest promise

This template will tell you where you stand. If you are below £1,000 of trading income, it will show you that you have nothing to declare and can stop worrying. If you are above it, it will show you exactly what you owe and what to set aside, so you can deal with it calmly rather than dreading it.

Either way, the worry goes away, because uncertainty is replaced with a number.

Get the UK Online Seller Tax Template, £14.99 →

Works in Google Sheets and Excel. One-time payment. No subscription. Built by an ACCA-qualified accountant using confirmed 2026/27 UK tax rates.

Disclaimer

The calculations in this template are based on confirmed UK tax rates and thresholds for the 2026/27 tax year. Tax legislation changes regularly and it is your responsibility to verify that the rates used remain current before relying on any figures produced by this template.

This template produces estimates only. The actual tax, National Insurance and student loan repayment you owe will depend on your full financial circumstances, including any other sources of income, reliefs, allowances or deductions that may apply to your specific situation and that this template does not account for.

This template does not constitute tax advice, financial advice or accountancy services. Rhodium Accounting accepts no liability for any tax underpayment, penalty, interest charge or financial loss arising from reliance on figures produced by this template. You remain solely responsible for ensuring your Self Assessment return is accurate and submitted on time.

If you are unsure about your tax position, you should seek advice from a qualified accountant or tax adviser before filing your return.