I note that fewer than 3,300 have registered with HMRC under the new money laundering regulations, which require agents to register with HMRC if not already supervised by the FSA or another designated professional body. Considering that HMRC's original estimate was in the region of 40,000, this is quite worrying.
The original estimate may well be inaccurate, but surely not that far out. HMRC must be able to make a reasonable estimate just based on the agents on their database. This suggests to me just one more area where unqualifieds are not keeping up to date.
HMRC should be able to systematically check whether each agent is registered or supervised elsewhere, but whether they actually will, or what action they will take with unregistered agents, waits to be seen.