If you don’t send your VAT Return and pay any VAT due on time, you will get a ‘VAT notice of assessment of tax’ from HM Revenue and Customs (HMRC), telling you how much VAT they think you owe.
What you need to do
Send your VAT Return and any payment due immediately.
If the assessed amount of VAT is too low you must tell HMRC within 30 days. Do this by sending a correct VAT Return and VAT payment or contacting them. You may be charged a penalty if you don’t.
If the assessment is too high, you can’t appeal it. You must send a correct VAT Return and VAT payment.