Barclays has set aside an extra £600 million to meet compensations claims for the mis-selling of payment protection insurance (PPI) in the third quarter.
The sum brings the total provision over the past two quarters alone to £1 billion, after £400 million was set aside in the second quarter.
The banking industry's PPI bill already stands at more than £30 billion.
Chief executive Jes Staley said the bank is still focused on selling down and disposing its hinterland businesses to concentrate on UK and US operations.
"The growing momentum in attaining our strategic goals means we can feel optimistic of our prospects of completing the restructuring," he added.
On Wednesday, Lloyds Banking Group announced that it set aside a further £1 billion to fund compensation claims for the mis-selling of PPI.
The partly state-owned lender said it has also accounted for a further £150 million to meet other conduct issues, including £100 million relating to packaged bank accounts.