HMRC’s internal guidance manuals were originally intended as instructions, later guidance, for HMRC staff and were not available externally until they were first published in 1994, for subscribers only.

So yes, we are now 25 years on from first publication, although they were not free to everyone until they were published on the (then) Inland Revenue - HMRC - website in 2002.

This means that many current tax professionals will have had access to them throughout their entire careers; others may find it difficult to remember a time when they were not available.