The present value, without deducting any plan assets, of expected future payments required to settle the obligation resulting from employee service in the current and prior periods. [Refer: Plan assets, at fair value]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2025-01-01
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-URIDate 2025-03-27

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- 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

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- Definition

The amount of deficit or surplus in a defined benefit plan, adjusted for any effect of limiting a net defined benefit asset to the asset ceiling. [Refer: Defined benefit plans [domain]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2025-01-01
-Paragraph 140
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-URIDate 2025-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
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- Definition

The fair value of defined benefit plan assets. Plan assets comprise assets held by a long-term employee benefit fund and qualifying insurance policies. [Refer: At fair value [member]]

+ References

+ Details

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- Definition

The amount of surplus in a defined benefit plan, adjusted for any effect of limiting a net defined benefit asset to the asset ceiling. [Refer: Defined benefit plans [domain]]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Note Expiry date 2027-01-01
-Name IAS
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-Paragraph 55
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-URIDate 2025-03-27

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- Definition

The amount of deficit in a defined benefit plan. [Refer: Defined benefit plans [domain]]

+ References

+ Details

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- Definition

The fair value of any plan assets, less the present value of the defined benefit obligation. [Refer: Plan assets [member]]

+ References

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- Definition

Irrecoverable Surplus, Restrictions On Assets Recognized

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No definition available.

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Net Defined Benefit Liability (Asset) Including Restrictions On Assets Recognized

+ References

No definition available.

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- Definition

Pensions and other post-retirement benefit obligations - Schedule of defined benefit plan recognised in balance sheet (Details) - GBP (£) £ in Millions	Sep. 30, 2026	Mar. 31, 2026	Sep. 30, 2025	Mar. 31, 2025
Disclosure of defined benefit plans [line items]
Other post-employment liabilities	£ (45)	£ (44)
Net defined benefit liability (asset) including restrictions on assets recognized	2,783	2,391
Restrictions on asset recognised	(492)	(244)
Net defined benefit asset	2,291	2,147	£ 2,075	£ 1,916
Assets	2,617	2,507
Liabilities	(326)	(360)
US
Disclosure of defined benefit plans [line items]
Funding surplus/(deficit)	1,416	1,385
Post-employment medical defined benefit plans \| US
Disclosure of defined benefit plans [line items]
Restrictions on asset recognised	(492)	(244)	£ (221)	£ (77)
Funded obligations
Disclosure of defined benefit plans [line items]
Present value of obligations	(14,127)	(15,098)
Fair value of plan assets	17,184	17,780
Funding surplus/(deficit)	3,057	2,682
Unfunded obligations
Disclosure of defined benefit plans [line items]
Present value of obligations	£ (229)	£ (247)