Your VAT registration number is nine digits and it is not something you choose or can look up by name. HMRC issues it when your registration is accepted, and from that moment it has to appear on every invoice you raise. That obligation is also the answer to the question: if you have ever invoiced since registering, you already have the number written down in several places.
The four places it lives
The VAT registration certificate HMRC issued when you registered, which also carries your effective date of registration and your first return period. Your VAT online account, which is the copy that survives a lost certificate. Every invoice you have raised since registering, because the number must be included on all of them. And your accounting software's company settings, if you set it up to print the number on invoices, which it must. Between them, at least one is nearly always recoverable.
If the certificate is gone
A lost certificate is an administrative problem rather than a tax one. The number itself has not changed and does not need reissuing: it is in your VAT online account, and your own past invoices carry it. What the certificate uniquely records is the effective date of registration, which matters if you are working out pre-registration input tax or checking which period your first return covered, and that is recoverable from the same account. Keep a copy with your VAT records, which have to be kept for six years anyway.
Getting a number in the first place
The number is issued at the end of registration, not applied for separately. You register, HMRC processes it, and the number arrives by post along with the effective date of registration and details of the first return. The gap between applying and receiving it is the awkward part of the process: you cannot show VAT on an invoice until you have the number, so the standard approach is to raise the invoice for the gross amount and reissue it showing the VAT once the number arrives, which leaves the customer paying the same total and able to reclaim.
Questions people ask about what is my vat number
How many digits is a UK VAT number?
Nine. Suppliers often print it with a GB prefix or with spaces, but the registration number itself is the nine digits.
Can I trade while I wait for my VAT number?
Yes, but you cannot show VAT on an invoice until the number arrives. The usual approach is to invoice the gross amount and reissue showing the VAT once you have the number, so the customer pays the same and can then reclaim.
Is the VAT number the same as my UTR?
No. The Unique Taxpayer Reference relates to Self Assessment or Corporation Tax. The VAT registration number is nine digits, issued separately, and is the one that goes on invoices.