Market risk	12 Months Ended
Market risk	Dec. 31, 2025
Market risk [Abstract]
Market risk	The Group’s policy is to optimise reward while managing its market risk exposures within the risk appetite defined by the Board. The Group market risk policy and procedures outlines the hedging process, and the centralisation of risk from divisions into Group Corporate Treasury (GCT), for example via the transfer pricing framework. GCT is responsible for managing the centralised risk and does this through natural offsets of matching assets and liabilities, and appropriate hedging activity of the residual exposures, subject to the authorisation and mandate of GALCO within the Board risk appetite. The hedges are externalised to the market by derivative desks within GCT and the Commercial Bank. The Group mitigates income statement volatility through hedge accounting. This reduces the accounting volatility arising from the Group’s economic hedging activities and any hedge accounting ineffectiveness is continuously monitored. The Group establishes hedge accounting relationships for interest rate risk components using cash flow hedges and fair value hedges. The Group is exposed to cash flow interest rate risk on its variable rate loans and deposits together with its floating rate subordinated debt. The derivatives used to manage the structural hedge may be designated into cash flow hedges to manage income statement volatility. The economic items related to the structural hedge, for example current accounts, are not eligible hedged items under IAS 39 for inclusion into accounting hedge relationships. The Group is exposed to fair value interest rate risk on its fixed rate customer loans, its fixed rate customer deposits and the majority of its subordinated debt. Hedge ineffectiveness arises during the management of interest rate risk due to residual unhedged risk. Sources of ineffectiveness, which the Group may decide to not fully mitigate, can include basis differences, timing differences and notional amount differences. The effectiveness of accounting hedge relationships is assessed between the hedging derivatives and the documented hedged item, which can differ to the underlying economically hedged item. The largest residual risk exposure arises from balances that are deemed to be insensitive to changes in market rates (including current accounts, a portion of variable rate deposits and investable equity), and is managed through the Group structural hedge. Consistent with the Group’s strategy to deliver stable returns, GALCO seeks to minimise large reinvestment risk, and to smooth earnings over a range of investment tenors. The structural hedge consists of longer-term fixed rate assets or interest rate swaps and the amount and duration of the hedging activity is reviewed regularly by GALCO. The Group’s exposure to pipeline and prepayment risks are managed through hedging in line with expected customer behaviour. These are appropriately monitored and controlled through divisional ALCOs. Economic foreign exchange exposures arising from non-functional currency flows are identified by divisions and transferred and managed centrally. The Group also has a policy of forward hedging its forecasted currency profit and loss to year end. The Group’s structural foreign currency exposure is represented by its investments in overseas subsidiaries and branches which create capital resources denominated in foreign currencies, principally USD and EUR. Gains or losses on structural foreign currency exposures are taken to reserves, resulting in a movement in CET1 capital. The Group’s main overseas operations are in America and Europe and do not represent a significant proportion on its overall portfolio. The Group manages foreign currency accounting exposure via cash flow hedge accounting, utilising currency swaps and forward foreign exchange trades. All non-structural foreign exchange exposures in the non-trading book are managed centrally within allocated exposure limits.