EAIG16500 | Who to assess: other excise assessments
From HM Revenue & Customs · Excise Assessments Interim Guidance
In most other excise legislation, the person to assess will be specified in the particular provision. For example
the proprietor when there is a deficiency in goods which have been lawfully permitted to be taken from a warehouse (CEMA section 95)
the producer or the supplier (depending on the specific circumstances) when there is unapproved mixing of oils (HODA section 20AAB(4)), or
the person who used the oil, or was liable for oil being taken into a road vehicle, in a case involving misuse of rebated heavy oil (HODA section 13(1A)).
But you still must ensure that you identify and assess the correct entity.