The bank, which is pushing ahead with previously announced branch closures including more than 70 in Scotland, has seen a rise in customer lending offset by impairments, restructuring costs and reduced consumer spending.
The Spanish-owned high street bank, which has its Scottish headquarters in Edinburgh, said it dived to the loss, from a £46m pre-tax profit the previous year, after the weak economic outlook resulted in a £164m impairment.
TSB said it saw total income fall by £90.1m, or 9.1 per cent, to £894.8m for 2020, after it was affected by the pandemic and restrictions.
It noted that this was also driven by reduced overdraft income, lower interest rates and a fall in consumer spending. Restructuring costs more than doubled to £90.6m for the year.
TSB axed 93 branches last year as part of its continued transformation plan, with some 600 employees affected as part of this process.
In September, the group announced plans to close a further 164 branches in 2021, including more than 70 north of the Border, with about 900 staff set to be made redundant.
The bank saw “record” lending growth during the year, rising by 7.2 per cent to £33.3 billion as the stamp duty holiday sparked mortgage growth and business lending was buoyed by the Bounce Back Loan Scheme.
Chief executive Debbie Crosbie said: “We’re ahead of plan in delivery of our strategy and have relaunched our brand.
“However, the impact of the pandemic and the additional cost of restructuring overshadows our financial result for the year.”