Knowing that the VAT threshold is £90,000 is the easy part. The questions that actually decide what you do, and when, are different: When exactly does the clock start? How many days do you have to tell HMRC? Should you jump early and register voluntarily before you're forced to? And what does the registration process itself involve?
This guide is about the timing and the mechanics of registering, not the threshold figure itself. It walks through the two registration tests and their deadlines, weighs up voluntary registration, and then takes you through how to register with HMRC step by step and what happens afterwards.
It applies whether you're a sole trader, a self-employed freelancer or an online seller, with extra notes for ecommerce businesses where the decision is often finely balanced. If you first need to work out whether you're even over the line, see our guides on the VAT threshold for the self-employed and exactly what counts towards the threshold for ecommerce sellers.
When must you register for VAT? The two tests {#when-must-you-register-for-vat}
The £90,000 threshold is measured on VAT-taxable turnover over a rolling 12-month period, not your profit and not the tax year. (If you need to confirm which of your sales count towards that figure, our guides on the VAT threshold for the self-employed and what counts for ecommerce sellers cover it in detail.) The point of this guide is timing: knowing the precise moment registration becomes compulsory.
There are two tests, and you must register if either is met:
- The backward look. At the end of any month, your VAT-taxable turnover for the previous 12 months has gone over £90,000.
- The forward look. You expect your VAT-taxable turnover to go over £90,000 in the next 30 days alone (for example, you've just won one big contract or a bulk order).
The forward look exists so a business can't dodge VAT by timing a single large sale. Most sole traders and online sellers cross the line on the backward look as turnover creeps up month by month, so that's the one to watch.
What are the registration deadlines and effective dates? {#registration-deadlines}
This is where the timing gets exact, and where late penalties come from.
Backward look. You have until the end of the month after the month you went over the threshold to tell HMRC. Your registration then takes effect from the first day of the second month after you went over.
Forward look. You must register by the end of that 30-day period, and your registration takes effect from the date you realised you would exceed £90,000.
Miss the window and HMRC can backdate the registration to the date you should have registered, charge the VAT you should have collected, and add a failure-to-notify penalty on top. That's a painful combination, especially if you've already spent the revenue and can't go back to customers for the VAT.
Illustrative example. Aisha runs a Shopify homeware shop as a sole trader. Her rolling 12-month sales pass £90,000 during March. Because she went over in March, she must tell HMRC by 30 April, and her registration takes effect from 1 May. The numbers here are illustrative; your own dates depend on the month you cross the threshold.
Should you register for VAT voluntarily? {#should-you-register-for-vat-voluntarily}
If you're under £90,000, voluntary registration is an option, and for many ecommerce businesses it's worth considering.
The case for going early:
- You can reclaim VAT on business purchases: stock, packaging, paid ads, website hosting, fulfilment costs. For sellers with real overheads, that can be a meaningful saving.
- You look more credible to larger wholesale suppliers and B2B clients who expect a VAT number.
- If you buy from lots of VAT-registered suppliers but sell mostly to consumers, the maths can work strongly in your favour.
The case against:
- You'll need to add 20% VAT to your prices. Consumer-facing businesses sometimes find this makes them less competitive.
- There's a quarterly admin commitment: returns, software and digital record-keeping.
- Once registered, you can't easily come off unless you drop below the £88,000 deregistration threshold.
In practice, if you're spending heavily on stock, ads or fulfilment, voluntary registration often pays for itself fast. If you sell low-cost goods direct to consumers on thin margins, the price impact deserves careful thought first. If you sell mainly to other businesses, see our guidance for ecommerce sellers.
How do you register for VAT, step by step?
The process is straightforward, but have the right information ready before you start.
- Log in to (or create) your Government Gateway account on gov.uk.
- Go to HMRC's VAT registration service.
- Complete the online form with your business details: your National Insurance number (for sole traders), Unique Taxpayer Reference, bank details, and an estimate of your expected turnover.
- Submit your application.
Most applicants receive their VAT number and registration certificate within 30 days. Once registered, you must charge VAT on all taxable sales and issue VAT invoices. You can register at the official HMRC VAT registration service.
Which VAT scheme should you choose at registration? {#which-vat-scheme-suits-your-ecommerce-business}
When you register you choose a VAT scheme, and the right one can save you time and money. Here's a plain comparison.
| Scheme | Best for | Key advantage | Main drawback | Ecommerce fit |
|---|---|---|---|---|
| Standard | High stock or ad spend | Full reclaim of input VAT | Full records and quarterly returns | High-volume stores with big costs |
| Flat Rate | Low overheads, simplicity | A fixed % of turnover, less admin | Limited input VAT reclaim | Smaller sellers, especially in year one |
| Cash Accounting | Slower payment cycles | Pay VAT when you're paid | Can't reclaim until you've paid suppliers | Service-based or small online shops |
| Annual Accounting | Stable, predictable turnover | One return a year | Advance payments required | Mature businesses with steady sales |
On the Flat Rate Scheme, you get a 1% reduction to your flat rate percentage for your first year of VAT registration, from the date you join the scheme up to the first anniversary of becoming VAT registered.
If your costs are low and you want simplicity, the Flat Rate Scheme and its first-year discount can be attractive. If you carry significant stock or spend heavily on ads, the Standard Scheme usually saves more through input VAT reclaims. The right answer depends on your margins and cost base, so it's worth modelling both before you commit.
What does Making Tax Digital for VAT mean for you?
Making Tax Digital (MTD) for VAT is mandatory for all VAT-registered businesses, including those who registered voluntarily. It has applied to all VAT-registered businesses since 1 April 2022.
In practice, it means two things:
- You must keep your VAT records digitally.
- You must file your VAT returns using HMRC-compatible software (a spreadsheet only works if it's linked to HMRC through bridging software).
The good news is that most accounting software handles this automatically and files directly to HMRC. HMRC keeps a list of compatible products, and you can find the approved MTD software list on gov.uk. If you're not already set up, sorting this out before you register is sensible.
Does incorporating reset the VAT threshold?
This comes up a lot from growing ecommerce sellers thinking about moving from sole trader to limited company. The short answer is usually yes, but with conditions.
When a sole trader transfers their business to a new limited company as a Transfer of a Going Concern (TOGC), the limited company can start with its own £90,000 threshold, and the sole trader's historical turnover doesn't automatically carry across. But there are important caveats:
- If you were already VAT-registered as a sole trader, you may be able to transfer that registration to the company rather than start fresh, and a TOGC can require the buyer to be (or become) registered.
- If you'd already gone over the threshold as a sole trader but hadn't registered, the obligation can follow the business, so you can't use incorporation to wipe the slate.
- TOGC has specific conditions that must all be met for the transfer to qualify.
This is one area where advice before you incorporate can save real money and hassle. Our corporation tax services team can walk you through it.
How do international sales affect your VAT?
Selling beyond the UK adds another layer. Here's a quick overview.
Selling to EU consumers. Since Brexit, the rules depend on what you sell and where. If you sell digital services to EU consumers, you may need to register for VAT in individual EU countries or use the EU's One Stop Shop (OSS) scheme. Thresholds and rules vary by country.
Selling to EU businesses. Goods exported to a business customer are typically zero-rated for UK VAT, provided you keep the right evidence. Keep your records.
Importing stock. Import VAT and customs duties are usually due at the point of import. If you hold stock in EU fulfilment centres, you may also have VAT obligations in those countries.
US or other international sales. Generally outside the scope of UK VAT, but the rules depend on where your customer is and what you're selling.
International VAT is complex and changes regularly. If you're selling in significant volumes abroad, dedicated cross-border advice is worth the investment.
How do you monitor turnover so you register on time? {#how-do-you-monitor-turnover-and-avoid-penalties}
The rolling 12-month rule catches sellers off guard, particularly those with seasonal spikes. Knowing when to register is only useful if you spot the moment you cross the line. Here's how to stay on top of it.
Keep a monthly tracker. A simple spreadsheet works: list each month's taxable revenue and keep a running 12-month total. Update it every month, not just at year-end. Most platforms (Shopify, WooCommerce, Amazon Seller Central) let you export monthly revenue in a few clicks.
Set yourself an alert at around £80,000. That gives you time to review your options before you're legally obliged to act.
Understand the penalty. If you register late, HMRC can charge a failure-to-notify penalty calculated as a percentage of the VAT you should have paid from the date you should have been registered (the "potential lost revenue"). The percentage depends on whether the failure was careless or deliberate and whether you came forward yourself. Telling HMRC before they come to you (an unprompted disclosure) usually means a lower penalty than if they find it first.
The deregistration threshold is currently £88,000. If your turnover drops below that figure, you can apply to deregister, though it isn't automatic.
Want to sanity-check where you stand? Try our self-employed tax calculator to see the bigger picture alongside your VAT position.
FAQs
Is the sole trader VAT threshold different from the standard threshold?
No. It's the same £90,000 figure for 2025/26, regardless of your business structure.
Do I charge VAT on quotes and invoices straight away?
Once you're registered, yes. Many businesses quote prices "plus VAT" while their application is in progress, then add VAT once their number is confirmed.
Can I reclaim VAT on home office costs or my car?
For genuine business use, yes. Home office costs can usually be reclaimed on a proportional basis. Cars are trickier: you generally can't reclaim VAT on a car bought for any private use, with limited exceptions, so check the position before you buy.
Does my ecommerce platform calculate VAT automatically?
Most major platforms handle VAT display at checkout once you add your VAT number to your account settings. You still need your own digital records for MTD purposes.
I'm close to £90,000. Should I turn down orders?
Please don't. That approach can damage your business and your customer relationships. Instead, plan ahead and talk to an accountant about voluntary registration or which scheme would suit you.
What's the difference between zero-rated and exempt for VAT?
Zero-rated sales (such as most food or children's clothes) count as taxable turnover and let you reclaim related input VAT. Exempt sales (such as certain financial services) don't count toward the threshold, but you also can't reclaim input VAT on related costs. It's an important distinction.
Talk to Zmartly about your VAT
Not sure whether to register, or which scheme fits your store? Book a free 20-minute call with a Zmartly accountant and we'll look at your numbers with you. See our self-assessment and tax services or get in touch at zmartly.co.uk.
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