Last reviewed: 30 May 2026
Quick summary
- You must register for VAT if your total taxable turnover for the last 12 months goes over £90,000, or if you expect it to go over £90,000 in the next 30 days. Voluntary registration may also be possible.
- Check the tax year, income source, records and threshold before relying on a broad rule.
- Use the preparation checklist on this page before speaking to an accountant.
Direct answer
You must register for VAT if your total taxable turnover for the last 12 months goes over £90,000, or if you expect it to go over £90,000 in the next 30 days. Voluntary registration may also be possible.
What this means in practice
- Taxable turnover is not the same as profit.
- Late registration can mean paying VAT from when you should have registered.
- Ask an accountant about pricing, cash flow, schemes and invoicing before registering voluntarily.
The best next step is usually to gather the facts before asking for advice: income, expenses, dates, software, previous returns and any HMRC letters. That gives an accountant something concrete to review.
What to prepare before speaking to an accountant
- Rolling 12-month taxable turnover.
- Expected sales for the next 30 days.
- Whether customers are VAT registered.
- Pricing and margin impact.
- Software and invoicing readiness.
Examples of how the answer can change
Compulsory registration is easier to assess when your sales are clearly taxable and you track rolling 12-month turnover each month.
VAT becomes more complex with mixed taxable and exempt sales, overseas sales, fast growth, voluntary registration, pricing pressure, flat-rate scheme questions or ecommerce channels.
The useful pattern is to separate facts from judgement. Facts are things like dates, turnover, software, invoices, bank statements, ownership and deadlines. Judgement is where a rule has to be applied to those facts. The more judgement involved, the more valuable a focused accountant conversation becomes.
How to use this guide before you speak to anyone
Prepare monthly taxable turnover, expected next-30-day sales, customer type, pricing impact, software readiness and any overseas or marketplace sales.
Then write down the decision you are trying to make in one sentence. For example, you might be trying to decide whether to file yourself, change software, register for VAT, switch accountant or clean up records before a deadline. A clear question helps an accountant respond more usefully and helps you compare answers from different providers.
Do not treat the first call as only a price check. Use it to test whether the accountant understands the situation, can explain the next step in plain English and can tell you what information they need before giving a firm view.
How to compare your options
It usually helps to compare three routes: doing it yourself, using software or bookkeeping support, and speaking to an accountant. The right route depends on the risk of getting it wrong, how much time you have, whether deadlines are close and whether the answer affects future tax or compliance.
DIY can be sensible when records are tidy, the rules are easy to check and the financial impact is modest. Software can help when the main issue is organisation, recurring transactions or digital records. Accountant support becomes more useful when interpretation, judgement, deadlines or business structure are involved.
When comparing accountants, ask for the scope in writing. A good comparison should tell you what is included, what is excluded, who will do the work, how quickly they respond, what records they need and whether they understand your business type.
A quick quality check before you decide
- Can you explain the issue in one sentence
- Do you have evidence for the figures or records involved
- Have you checked the official guidance linked on this page
- Would a mistake create penalties, extra tax, missed deadlines or messy records next year
- Do you know what you want an accountant to answer
If several of those answers are unclear, the next step is not necessarily a long engagement. It may simply be a short accountant conversation to confirm the right route and avoid building the rest of the year on a weak assumption.
What this guide is focusing on
Use this guide if you are a business owner watching sales rise and worrying whether VAT is based on profit, payouts or taxable turnover. For When should I register for VAT, focus on how the rule meets the records, thresholds, software and decisions you actually have in front of you.
What figure, record or decision should you pin down?
Pin down rolling 12-month taxable turnover, expected next-30-day sales, customer type, pricing impact, refunds, marketplace fees and software readiness. That gives an accountant something specific to check and stops the conversation becoming a vague discussion about tax in general.
Records to gather
- monthly taxable turnover
- next-30-day expected sales
- customer mix
- refunds and exempt or zero-rated sales
- invoicing software readiness
Real examples for this situation
- A marketplace seller may receive a payout after fees, but VAT turnover starts with taxable sales rather than the payout.
- A consultant with one large upcoming contract may need the next-30-day test before the rolling 12-month total catches up.
- A business selling mostly to VAT-registered customers may think differently about pricing than one selling to consumers.
A common mistake is waiting until annual accounts are prepared instead of monitoring rolling turnover each month. The safest pattern is to write down the figure, source, date and evidence before deciding whether DIY, software or accountant support is enough.
When to speak to an accountant
Speak to an accountant before registering voluntarily, if you are near the threshold, if sales are growing quickly, or if VAT will affect pricing and cash flow.
Questions to ask an accountant
- What counts as taxable turnover for me
- When exactly would registration start
- Should I consider voluntary registration
- Which VAT scheme might fit
- How should invoices and software change
Mistakes to avoid
- Looking only at annual profit.
- Missing the rolling 12-month test.
- Registering voluntarily without pricing analysis.
- Leaving invoicing changes until after registration.
Key takeaway
You must register for VAT if your total taxable turnover for the last 12 months goes over £90,000, or if you expect it to go over £90,000 in the next 30 days. Voluntary registration may also be possible. If the facts are not simple, use this as a prompt for a proper accountant conversation rather than a final personal answer.
Official guidance checked on 30 May 2026
Use these links to check current rules, thresholds and deadlines. They were checked during the current content pass, but should be rechecked before important decisions.
Related guides
Related accountancy pages
FAQs
How should I use this guide
Use it to understand the issue, gather useful records and prepare better questions for an accountant.
What should I check before acting
Check current GOV.UK or HMRC guidance, your own records and whether your circumstances have details that change the answer.
When is it worth speaking to an accountant
When the decision affects tax, deadlines, VAT, MTD, company structure, property income, payroll, software setup or anything you are not confident checking yourself.
Keep this current
Tax rules and thresholds can change. Check the linked official guidance and speak to an accountant before making important decisions.