HMRC has published its TP statistics for the year to 31 March 2019. An outline of the numbers and trends is relatively simple to report (for example here). It is also possible to ‘lift the lid’ a little and think about what these all mean in practical terms.
1 The ‘average’ time to settle TP enquiries was 33 months.
For the previous year an average TP enquiry took 24 months. Also, these are ‘means' not ‘medians’ and they are ‘simple’ not ‘weighted’. Add to that the fact that no enquiry lasts 0 months (possibly 12 at a low end, but these are rare) and a few things become clear.
First, the distribution has to be a large clump at, say, 18-36 months with a long tail to the right.
Second, that the long tail is probably composed of the larger, more complex cases. If the simple average is almost three years, the weighted average must be four or more. Say 4-5.