TRSM25010 | Types of trust that need to be registered: contents: registrable taxable trusts: contents: requirements for registration
From HM Revenue & Customs · Trust Registration Service Manual
Alongside the requirements to register as registrable express trusts, trusts may be required to register if they have a liability to UK taxation. The exclusions from registering as an express trust do not apply here.
Trusts are required to register as taxable trusts if both of the following apply:
These trusts must register on the Trust Registration Service (TRS) and provide information as set out in TRSM32000.