John Rumm wrote:

If you install fixed equipment then it still counts IIUC.

Yep, even if the connection is by 13 A plug and socket (as made clear by
item h. in the list of "additional notes" on page 9 of the Approved
Document).

However business premises etc would not because Part P is domestic only...

Unless the business supply (i.e. DNO's cut-out, and metering) is shared
with a dwelling.

--
Andy