The Post Office has agreed to extend its deal to use the controversial Horizon IT system for another year.
It is paying a further £41m to the Japanese-owned company Fujitsu to use Horizon until March 2027.
The accounting system has been at the centre of the Post Office scandal in which more than 900 sub-postmasters were wrongly prosecuted after faulty Horizon software made it look like money was missing from their branch accounts.
A Post Office spokesperson said it was "committed to moving away from Fujitsu and off the Horizon system as soon as possible".