IHTM14132 | Lifetime transfers: specific lifetime exemptions: order in which exemptions apply
From HM Revenue & Customs · Inheritance Tax Manual
Where several of the exemptions that apply solely to lifetime transfers (IHTM14131) are available, and where the transfers in that year exceed the annual exemption limit:
apply IHTA84/S21, normal expenditure out of income (IHTM14231) exemption, first on a purely factual basis, without regard to any other exemption, limited or unlimited
apply IHTA84/S19, the annual exemption (IHTM14141), last after all the other available exemptions have been applied to the transfer.
If the taxpayer asks you to adopt a different order of application of the exemptions, refer the case to your manager.