Hi,
If a business believes that they have overpaid VAT on their VAT returns then they must submit an error correction to HMRC. You should submit this correction as quickly as possible after discovering the error. HMRC will be unable to process any refund of overpaid VAT without the VAT returns being corrected.
How to correct VAT errors and make adjustments or claims (VAT Notice 700/45)
If you are worried about being able to meet VAT payments owed to HMRC, or you anticipate that payments coming due will cause problems, we would encourage you to set up a self service time to pay arrangement while the situation is resolved. You can do this online. If you cannot set up a time to pay arrangement online, you can also contact HMRC’s debt management team.
If you believe your business is established in the UK but have concerns that this is not correctly shown on HMRC systems or if the marketplace has requested you update your VAT details with HMRC to show you are UK established, then please contact:
isbcvatestablishment@hmrc.gov.uk
Thank you.