Disclosure Of Entity's Operating Segments [Text Block]

SANTANDER UK PLC - Filing #1571969

Concept	2021-01-01 to 2021-12-31	As at 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2020-01-01 to 2020-12-31	As at 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2019-01-01 to 2019-12-31	2019-01-01 to 2019-12-31	2019-01-01 to 2019-12-31	2019-01-01 to 2019-12-31
Disclosure of entity's operating segments [text block]	—	—	—	—	—	—	—	—	—	—	—	—	—	—
Disclosure of operating segments [text block]	—	—	—	—	—	—	—	—	—	—	—	—	—	—
Disclosure of operating segments [abstract]
Disclosure of operating segments [line items]
Interest income	—	—	—	4,762,000,000 GBP	—	—	—	5,031,000,000 GBP	—	—	—	—	5,817,000,000 GBP	—
Interest expense	—	—	—	813,000,000 GBP	—	—	—	1,643,000,000 GBP	—	—	—	—	2,593,000,000 GBP	—
Interest income (expense)	—	—	—	3,949,000,000 GBP	—	—	—	3,388,000,000 GBP	—	—	—	—	3,224,000,000 GBP	—
Tax expense (income)	—	—	—	492,000,000 GBP	—	—	—	121,000,000 GBP	—	—	—	—	268,000,000 GBP	—
Profit (loss) from continuing operations	—	—	—	1,353,000,000 GBP	—	—	—	439,000,000 GBP	—	—	—	—	703,000,000 GBP	—
Profit (loss)	19,000,000 GBP	—	1,365,000,000 GBP	1,384,000,000 GBP	1,365,000,000 GBP	452,000,000 GBP	—	471,000,000 GBP	19,000,000 GBP	452,000,000 GBP	714,000,000 GBP	714,000,000 GBP	733,000,000 GBP	19,000,000 GBP
Assets	—	287,098,000,000 GBP	—	—	—	—	292,332,000,000 GBP	—	—	—	—	—	—	—
Liabilities	—	270,996,000,000 GBP	—	—	—	—	276,396,000,000 GBP	—	—	—	—	—	—	—
Cash flows from (used in) operating activities	—	—	—	10,846,000,000 GBP	—	—	—	18,823,000,000 GBP	—	—	—	—	4,030,000,000 GBP	—
Cash flows from (used in) investing activities	—	—	—	3,077,000,000 GBP	—	—	—	6,636,000,000 GBP	—	—	—	—	2,890,000,000 GBP	—
Cash flows from (used in) financing activities	—	—	—	10,753,000,000 GBP	—	—	—	6,773,000,000 GBP	—	—	—	—	4,180,000,000 GBP	—