VAEC1230 - Powers of assessment: VAT assessment powers: Risk of delay
Delays by HMRC in making or issuing assessments can frustrate businesses and may lead to disputes or an appeal to a Tribunal on time limits grounds.
On the other hand, delays by businesses in providing information upon which to base an assessment can cause periods to fall out of time.
To avoid these problems, it is best practise to ensure you are in a position to make and notify your assessment within one year of the visit.
Note: If the last day of the prescribed accounting period for which you are considering an assessment is approaching four years, you may not have a full year or anything like as long during which to assess.
This is because periods are still going out of time under the four year rule even while you are collecting the evidence or information on which to base the assessment.