Other operating expenses - Charges in Respect of Nigerian FCCPC Case - Additional Information (Details) £ in Millions	12 Months Ended
Dec. 31, 2022 GBP (£)
Nigerian court \| Competition investigations
Other Operating Expenses [Line Items]
Other adjusting items in other operating expenses	£ 79

Other adjusting items which have been adjusted within other operating expenses.

No definition available.

Name:	bti_OtherAdjustingItemsWhichHaveBeenAdjustedWithinOtherOperatingExpenses
Namespace Prefix:	bti_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration