For information I've just received this message from HMRC
"Trusts and estates: trust details (41G (Trust))
11:02am, 19 May 2017 Form 41G(Trusts) has been withdrawn.
Registration form 41G(Trust) is no longer in use.
Form 41G (Trust) has been withdrawn and will be replaced during summer 2017 by a new registration service. When this is available all trusts with a tax liability should use it to register with HM Revenue and Customs (HMRC).
You can find more information about the new service and when to register your trust with HMRC in the April Trusts and Estates newsletter. You can also contact HMRC Trusts service for specific advice about registering your trust or estate."
Note "has been withdrawn" and "will be replaced during summer 2017"!!
Andrew M Mortimer