TSEM1472 | Introduction to trusts: new trust: administration period followed by a trust
From HM Revenue & Customs · Trusts, Settlements and Estates Manual
The period of administration starts at the date of death. It finishes when the personal representatives have discharged all their duties (TSEM6071) and CG30700.
If there is a trust, BT & C Trusts will deal with the trust. (TSEM1420)