Dividends (Tables)

12 Months Ended

Dec. 31, 2019

Interim Financial Reporting [Abstract]

Disclosure of dividends announced and paid

	Pence per share			Cents per share					$ million
	2019	2018	2017	2019	2018	2017	2019	2018	2017
Dividends announced and paid in cash
Preference shares							1	1	1
Ordinary shares
March	7.7380	7.1691	8.1587	10.25	10.00	10.00	1,435	1,828	1,303
June	8.0660	7.4435	7.7563	10.25	10.00	10.00	1,779	1,727	1,546
September	8.3480	7.9296	7.6213	10.25	10.25	10.00	1,656	1,409	1,676
December	7.8250	8.0251	7.4435	10.25	10.25	10.00	2,075	1,734	1,627
	31.9770	30.5673	30.9798	41.00	40.50	40.00	6,946	6,699	6,153
Dividend announced, paid in March 2020				10.50			2,120

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 the third quarter 2019 dividend paid in December 2019 and fourth quarter 2019 dividend expected to be paid on 27 March 2020.

	2019	2018	2017
Number of shares issued (thousand)	208,927	195,305	289,789
Value of shares issued ($ million)	1,387	1,381	1,714