I too have had this issue.
I raised this with one of HMCTS’s Operational Delivery and Business Support Officers who’s response to my point about unnecessary waiting times if the IHT421 was now with HMCTS was:
"*Apologies, but these are individual cases which may have been processed by HMRC slightly more quickly. *
*We are being led by HMRC and their data as to how quickly they are processing applications. *
*It is not feasible to build into these confirmation letters (the letters HMRC sends to yourselves) unique identifiers that can then be ratified by our system to confirm that a 421 has been received or not. *
*Thus, there is at present the blanket wait, which will be tweaked accordingly with any changes in operational timeliness at HMRC. *
*We are in the early stages of working on the automation of linking IHT421’s to our system. This is facilitated by HMRC now sending the 421 direct to HMCTS. When this work in complete, there will be further significant improvements. *
I sympathise and completely understand your perspective, but to ensure improved timeliness for all applications, we ask that you wait these 20 working days. This is the time currently required for HMCTS to be sure that upon first examining an application, the IHT421 will be present. Please continue to observe this wait period as this will help ensure efficiency more generally, but also ensures that your application doesn’t go to the bottom of a pile of Stopped cases if the IHT421 were not to be present."
Not ideal, so I too ‘fudged’ the date to avoid further delay for my clients.