You register for VAT online through your HMRC business tax account. Most straightforward registrations take about 30 days to process, though it can take longer if HMRC needs to check anything - and you cannot charge VAT until your registration is confirmed, even if you know it is coming.
Before you start: what you need
Your business details - legal name, trading name (if different), and address
Your Unique Taxpayer Reference (UTR) if you are already registered for Self Assessment or Corporation Tax
Your bank account details for the business
An estimate of your expected turnover for the next 12 months
Details of any associated businesses you own or have owned in the last 2 years
The registration steps
Create or sign in to your Government Gateway account at gov.uk
Choose the correct registration route - most sole traders and small companies register directly online rather than by post
Enter your business and turnover details, and choose your VAT accounting scheme (standard, Flat Rate, Cash Accounting, or Annual Accounting)
Submit the application - HMRC will confirm your effective date of registration and issue your VAT registration number
Update every invoice template, quote, and price list to include VAT from your effective date
What happens between applying and getting your VAT number
This is the part that catches people out. Your effective registration date is fixed the moment HMRC processes your application - but the VAT number itself can take a few weeks to arrive. If you cross that effective date before your number shows up, you still owe VAT on sales from that date; you just cannot show a VAT number on invoices yet. HMRC's guidance calls this the "VAT registration in progress" period, and it is completely normal - you issue an interim invoice without VAT shown, then send a VAT-only invoice for the difference once your number arrives.
What changes the moment you are registered
Every invoice you send from your effective date needs your VAT number, the VAT rate applied per line, the VAT amount, and the net and gross totals shown separately. There is no grace period for old-format invoices - this applies to the very first one after registration, not just ones you send after your VAT number physically arrives.
This is the exact switch Invoito is built to make painless: mark your business as VAT registered in Settings, add your VAT number once it arrives, and every invoice from that point calculates and displays VAT correctly - including any interim invoices you need to issue while you're waiting.
How long does VAT registration take?
Most online applications are processed within 30 days, though HMRC can take longer if it needs to verify any details. You will not be able to charge VAT until the registration is confirmed.
Can I register for VAT myself, or do I need an accountant?
What if I go over the threshold before my registration comes through?