Dividends (Tables)

12 Months Ended

Dec. 31, 2020

Interim Financial Reporting [Abstract]

Disclosure of dividends announced and paid

	Pence per share			Cents per share					$ million
	2020	2019	2018	2020	2019	2018	2020	2019	2018
Dividends announced and paid in cash
Preference shares							1	1	1
Ordinary shares
March	8.1558	7.7382	7.1691	10.50	10.25	10.00	2,102	1,435	1,828
June	8.3421	8.0655	7.4435	10.50	10.25	10.00	2,119	1,779	1,727
September	4.0433	8.3475	7.9296	5.25	10.25	10.25	1,059	1,656	1,409
December	3.9169	7.8250	8.0251	5.25	10.25	10.25	1,059	2,075	1,734
	24.4581	31.9762	30.5673	31.50	41.00	40.50	6,340	6,946	6,699
Dividend announced, paid in March 2021				5.25			1,067

The details of the scrip dividends issued are shown in the table below. The board decided not to offer a scrip dividend alternative in respect of any dividends announced since the third quarter 2019, including the fourth quarter 2020 dividend expected to be paid on 26 March 2021.

	2020	2019	2018
Number of shares issued (thousand)	—	208,927	195,305
Value of shares issued ($ million)	—	1,387	1,381