Call Options, Term

No definition available.

Name:	bti_CallOptionsTerm
Namespace Prefix:	bti_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Costs (Reversal) Relating To Assets Held-For-Sale

+ References

No definition available.

+ Details

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

- Definition

Disposal Group, Transaction Costs

+ References

No definition available.

+ Details

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

- Definition

Gains (Losses) Recognized When Control of Subsidiary is Lost, Net of Reversal of Impairment Loss Recognized in Profit or Loss, Property, Plant and Equipment

+ References

No definition available.

+ Details

Name:	bti_GainsLossesRecognizedWhenControlOfSubsidiaryIsLostNetOfReversalOfImpairmentLossRecognizedInProfitOrLossPropertyPlantAndEquipment
Namespace Prefix:	bti_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Impairment charges and associated costs.

+ References

No definition available.

+ Details

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

- Definition

Number Of Subsidiaries

+ References

No definition available.

+ Details

Name:	bti_NumberOfSubsidiaries
Namespace Prefix:	bti_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table.

+ References

No definition available.

+ Details

Name:	ifrs-full_DisclosureOfBusinessCombinationsLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The gross gain arising from exchange differences recognised in profit or loss, excluding those arising on financial instruments measured at fair value through profit or loss in accordance with IFRS 9. [Refer: Foreign exchange gain (loss)]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 21
-IssueDate 2024-01-01
-Paragraph 52
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=21&code=ifrs-tx-2024-en-r&anchor=para_52_a&doctype=Standard
-URIDate 2024-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2024-01-01
-Paragraph 35
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_35&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_ForeignExchangeGain
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow from the disposal of non-current assets or disposal groups classified as held for sale and discontinued operations. [Refer: Discontinued operations [member]; Disposal groups classified as held for sale [member]; Non-current assets or disposal groups classified as held for sale]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 7
-IssueDate 2024-01-01
-Paragraph 16
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2024-en-r&anchor=para_16&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_ProceedsFromDisposalOfNoncurrentAssetsOrDisposalGroupsClassifiedAsHeldForSaleAndDiscontinuedOperations
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of reclassification adjustments related to exchange differences when the financial statements of foreign operations are translated, before tax. Reclassification adjustments are amounts reclassified to profit (loss) in the current period that were recognised in other comprehensive income in the current or previous periods. [Refer: Other comprehensive income]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 21
-IssueDate 2024-01-01
-Paragraph 48
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=21&code=ifrs-tx-2024-en-r&anchor=para_48&doctype=Standard
-URIDate 2024-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2024-01-01
-Paragraph 92
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_92&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_ReclassificationAdjustmentsOnExchangeDifferencesOnTranslationBeforeTax
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount reversed for unused other provisions. [Refer: Other provisions]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 37
-IssueDate 2024-01-01
-Paragraph 84
-Subparagraph d
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=37&code=ifrs-tx-2024-en-r&anchor=para_84_d&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_UnusedProvisionReversedOtherProvisions
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=bti_RussianAndBelarusianBusinessesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfIntangibleAssetsAndGoodwillAxis=ifrs-full_BrandNamesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bti_DetailsOfTheEntityBeingDisposedOffAxis=bti_BATRussiaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ContinuingAndDiscontinuedOperationsAxis=ifrs-full_DiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=country_RU
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Changes in the Group - Assets Held For Sale and Business Disposals (Details) £ in Millions		12 Months Ended
	Sep. 13, 2023 GBP (£) subsidiary	Dec. 31, 2024 GBP (£)	Dec. 31, 2023 GBP (£)	Dec. 31, 2022 GBP (£)	Mar. 11, 2022 subsidiary
Disclosure Of Business Combinations [Line Items]
(Reversals)/charges in respect of assets held-for-sale		£ 0	£ (195)	£ 612
Foreign exchange gain (loss) reclassified from other comprehensive income on disposal of business		£ 0	(552)	(5)
Russian and Belarusian Businesses
Disclosure Of Business Combinations [Line Items]
Proceeds from disposal	£ 425
Unused provision reversed, other provisions			(195)
Foreign exchange gain (loss) reclassified from other comprehensive income on disposal of business			554
Gain (loss) on disposal, net of impairment reversal			353
Associated costs			3
Foreign exchange gain			£ (9)
Call options, term			2 years
Russian and Belarusian Businesses \| Brand names
Disclosure Of Business Combinations [Line Items]
Call options, term			100 years
BAT Russia \| Discontinued operations
Disclosure Of Business Combinations [Line Items]
Impairment charges and associated costs				554
(Reversals)/charges in respect of assets held-for-sale				£ 58
Russia
Disclosure Of Business Combinations [Line Items]
Number of subsidiaries \| subsidiary	2				2