The obligation does not move, and two guidances get mixed up
Whoever prepares it, a registered agent reviews and signs it, and the responsibility for what is in the return stays where it was. The TPB’s guidance on outsourcing and offshoring — TPB(GS) 31/2018, which was TPB(PN) 2/2018 until the 2026 renaming — deals with disclosure to the client, supervision, and the security of client information sent to someone else.
The confusion worth clearing up: TPB(GS) 55/2026, the AI guidance, does not address offshoring at all. They are different documents about different questions, and each gets cited at the wrong one. We keep both, with links to the source, on the FAQ — including where the obligation sits between a provider and a practitioner, which is the part most sales conversations are vague about.
The practical consequence is the same for a person and for a piece of software: you have to be able to tell a client who handled their information and where. A provider who cannot answer that in a sentence has not thought about it, and neither has a vendor.