CH402750 | Charging Penalties: establishing penalty behaviour: obtaining information from a third party
From HM Revenue & Customs · Compliance Handbook
In some cases, where you suspect deliberate behaviour, you may need to seek information about penalty behaviour from a third party. For example, to check a person’s claim that they were following professional advice, you may need to ask the professional for copies of correspondence.
You can issue a third party notice using information powers in Sch36, FA08, see CH225000.
If your check is into excise duties you can issue an excise information notice, see CH228000.