EM1814 | Working the Enquiry: Keeping Control: Avoiding Delay by Taxpayer
From HM Revenue & Customs · Enquiry Manual
In some enquiries the volume and complexity of the information and of the issues that arise make it inevitable that the enquiry takes a long time. But in other cases the time taken to complete the enquiry is unnecessarily long. This could be burdensome for the taxpayer and is frequently a factor in complaints about enquiry work.
Enquiries inevitably take time, but your enquiry will be unnecessarily prolonged if
effective action is not taken to overcome delays by the taxpayer or agent.
You, taxpayers and their agents should aim to work within a 15 working day turnaround time. This may not always be possible but you should encourage agreement of a realistic timetable at the beginning of an enquiry to reflect needs or difficulties.