v3.26.1
Cover Page
6 Months Ended
Jun. 30, 2026
Cover [Abstract]  
Document Type 6-K
Entity Registrant Name SANTANDER UK PLC
Amendment Flag false
Document Period End Date Jun. 30, 2026
Document Fiscal Year Focus 2026
Document Fiscal Period Focus Q2
Entity Central Index Key 0001087711
Current Fiscal Year End Date --12-31