v3.26.1
DEBT SECURITIES IN ISSUE (Tables)
 6 Months Ended
Jun. 30, 2026
Debt Securities In Issue [Abstract]  
Summary of Debt Securities in Issue
30 June 2026
31 December 2025
£m
£m
Medium-term notes
2,220
2,290
Downstreamed from Santander UK Group Holdings plc to Santander UK plc
10,498
9,606
Euro €35bn Global Covered Bond Programme
18,073
19,201
£10bn Global Covered Bond Programme 
3,713
–
US $20bn Commercial Paper Programmes
2,264
2,411
Certificates of deposit
2,511
1,607
Credit linked notes
705
635
Securitisation programmes
7,271
5,638
47,255
41,388