Branch pin pads out of action. Emergency payments made to pensioners and benefits claimants.
A blip in a computer system is affecting transactions at Post Office branches.
In Honiton, pin pad machines have been out of action for two days.
Special arrangements have been made to for emergency cash payments to pensioners and benefit claimants using the Post Office Card Account.
The Post Office has today apologised to customers and says its 11,820 branches will remain open.
However, transactions involving Post Office Card Accounts, and debit and credit cards using the pin pads at branch counters are affected.
Commercial director Martin Moran said: “We apologise to customers for any inconvenience.
“We are making every effort to restore these services as soon as possible.”
Customers can continue to withdraw cash from any of the Post Office 2,000 ATMs, which are unaffected by this problem.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here