VAT registration is one of the most significant compliance milestones for a growing UK company. Get it right and it’s straightforward to manage. Miss the deadline or misunderstand the rules and you can find yourself owing VAT you haven’t collected, facing penalties, and unpicking months of invoices.

If you’re searching for how to VAT register a company, you’re probably in one of two situations: your turnover is approaching or has crossed the £90,000 mandatory threshold, or you’re considering voluntary registration before you get there. Either way, the process itself is the same — it’s done online through HMRC’s Government Gateway — but the timing, the preparation, and the downstream obligations differ depending on your circumstances.

This guide covers the threshold rules, the step-by-step registration process, what to expect in terms of timing, the VAT schemes worth knowing about, and the mistakes that catch companies out. It’s written for UK limited company directors and sole traders, so the examples and context are aimed at owner-managed businesses rather than large corporates.

As of the 2024–25 tax year, the mandatory VAT registration threshold is £90,000 of taxable turnover in any rolling 12-month period. This figure has been frozen at that level and remains in place as of August 2026. If you’re uncertain whether it has changed, check HMRC’s current guidance.

The 12-month look-back is rolling, not calendar-based. That means you’re not assessing the tax year — you’re looking at any consecutive 12-month window. So if your turnover in the 12 months ending on the last day of any given month has exceeded £90,000, the registration obligation is triggered.

When does the clock start?

You must register within 30 days of the end of the month in which you exceeded the threshold. For example, if your cumulative 12-month turnover crosses £90,000 during June, you have until 31 July to register. Your effective date of registration will then be 1 August — the first day of the following month.

Forward-looking test

There’s a second test that catches businesses off guard. If you have reasonable grounds to believe your taxable turnover will exceed £90,000 in the next 30 days alone — for instance, you’ve just signed a large contract — you must register immediately. The effective date is the start of that 30-day period, not the end of the month.

What counts as taxable turnover?

Taxable turnover includes sales of standard-rated (20%), reduced-rate (5%), and zero-rated goods or services. It does not include exempt supplies (such as most financial services, insurance, and certain types of land and property transactions), or sales that are outside the scope of VAT entirely. If your business sits across both taxable and exempt supplies, the calculation becomes more involved and it’s worth taking specific advice.

You can register for VAT at any time, even if your turnover is well below £90,000. Whether this makes sense depends on your business model, your customers, and your cost base.

The case for registering early

If most of your customers are VAT-registered businesses, they can reclaim the VAT you charge them — so adding 20% to your invoices doesn’t reduce your competitiveness. In that scenario, voluntary registration lets you reclaim the VAT you pay on your own costs: software subscriptions, equipment, professional fees, office costs. For a company spending a meaningful amount on VATable purchases, this can represent a real cash saving each quarter.

There’s also a reputational angle for some businesses — having a VAT number can signal that a business is established and trading at scale, though this is a secondary consideration at best.

The case against registering early

If your customers are primarily individuals or non-VAT-registered small businesses, voluntary registration raises your prices by 20% unless you absorb the VAT yourself — neither option is ideal when you’re competing on cost. You also take on the administrative burden of VAT accounting, quarterly returns, and Making Tax Digital compliance before you’re required to.

A construction contractor whose clients are private homeowners, for instance, has much less to gain from early registration than a management consultant billing corporate clients. The right answer genuinely depends on your specifics.

Pre-registration input tax

One often-missed benefit of voluntary registration: you can reclaim VAT on certain costs incurred before your registration date — up to four years for goods still on hand, and six months for services. This can be particularly worthwhile if you’ve bought equipment, tooling, or other capital items in the run-up to starting to trade.

Before you sit down to complete the VAT registration, it helps to have the right information to hand. Incomplete applications are a common cause of delay.

For a limited company

• Your company’s Unique Taxpayer Reference (UTR) — this is issued by HMRC after Companies House incorporation, usually within a few weeks. You cannot register for VAT online before you have it.
• Your Companies House registration number.
• The company’s registered address and principal place of business (these may differ).
• Bank account details for the business.
• Details of the nature of your trade — you’ll need a description of what your company does and a Standard Industry Classification (SIC) code.
• Your estimated taxable turnover for the next 12 months.
• The date your turnover exceeded (or is expected to exceed) the threshold — this becomes your effective date of registration.

For a Government Gateway account

You’ll need a Government Gateway user ID to complete the registration. If your limited company doesn’t already have one, you’ll create it during the process. Directors registering on behalf of a company should use an organisation account, not a personal one. This is a common source of confusion when the director has previously set up a personal Government Gateway for their own Self Assessment.

If the portal isn’t working

HMRC’s VAT registration portal has been reported as intermittently unavailable — a frustrating reality acknowledged by practitioners and HMRC itself. If you hit an error, try clearing your browser cache and cookies, or switching to a different browser such as Microsoft Edge. If the issue persists, try again at a different time of day. HMRC is actively working to improve and automate the registration system throughout 2026–27, so reliability should improve over time.

Standard VAT accounting — charging VAT on sales, reclaiming on purchases, and paying the difference to HMRC each quarter — is the default. But several VAT schemes exist that can simplify administration or improve cash flow for the right business.

Flat Rate Scheme

Available to businesses with taxable turnover below £150,000. Instead of calculating VAT on every individual transaction, you apply a fixed percentage to your gross (VAT-inclusive) turnover and pay that to HMRC. The percentage varies by trade sector, and you keep any difference between the flat rate you pay and the 20% you charge customers. It simplifies bookkeeping considerably, though it’s less advantageous if your business has high VATable costs — you can’t reclaim input tax under the scheme (except on certain capital goods over £2,000).

Cash Accounting Scheme

Available to businesses with taxable turnover below £1.35 million. Under this scheme, you account for VAT when you receive payment from customers and when you pay suppliers — rather than when invoices are raised. This is a cash flow benefit for businesses with slow-paying clients, as you’re not paying VAT to HMRC before the cash has come in.

Annual Accounting Scheme

Also available below £1.35 million. You submit one VAT return per year rather than four, making nine interim payments on account based on your prior year’s liability. Useful for businesses that want to reduce the administrative frequency of returns, though it can make it harder to keep a close eye on your VAT position throughout the year.

Making Tax Digital

All VAT-registered businesses must keep digital records and submit returns through Making Tax Digital (MTD)-compatible software. If your accounting software isn’t already MTD-compliant, you’ll need to address this before you start submitting returns. Xero and QuickBooks Online — both used by Supreme Consulting — are fully MTD-compliant and integrate directly with HMRC.

HMRC’s current guidance suggests VAT registration applications take up to 40 working days to process — roughly eight to ten calendar weeks. In practice, straightforward applications are sometimes processed more quickly, but delays beyond the quoted timeframe do happen and can be a real problem for businesses that need to start invoicing with VAT immediately.

During the processing window, you can ask customers to pay VAT by issuing a VAT receipt once your number comes through — provided you’ve made it clear the VAT charge is being applied. You should also be keeping track of any VAT you’ve charged in the interim, as it will need to appear on your first return.

HMRC does not routinely issue status updates while an application is being assessed. If you call, you’re likely to be told only that the application is still under review. This is a genuine frustration, particularly for businesses that need a VAT number to begin trading with certain clients or to register with online marketplaces.

One practical option if you need a VAT registration handled urgently is to appoint an agent — your accountant — to manage the application on your behalf. An experienced agent has direct access to HMRC agent lines and will often have better visibility of the application’s progress than the business owner calling the main helpline.

HMRC has confirmed it is investing in automating and streamlining the VAT registration process as part of its broader digitalisation programme, with improvements planned throughout 2026–27. Whether that translates to meaningfully faster turnaround times in practice remains to be seen.

Once you have everything in order, the registration itself is completed online. Here’s the process from start to finish.

VAT registration sounds straightforward, but these are the errors we see most often in practice.