Since Tuesday, many thousands of customers can no longer pay with giro or credit cards at German retailers.

Among other things, branches of Aldi Nord, Edeka or the Edeka subsidiary Netto are affected.

The reason for this is a malfunction in the widespread Verifone device H5000.

It is used by Payone and its competitor Concardis, among others.

The service providers provide the devices and process the payments.

The terminals themselves and the software for them come from Verifone.

The company announced on Friday that it would provide an update "soon".

Manual intervention on site by either the retailer or a technician is required to restart the devices, Payone said, citing Verifone.

All available resources for the update have already been pulled together.

"Nevertheless, we assume that this process cannot be carried out ad hoc in the area, but will probably take a few days," said a Payone spokeswoman.

Irrespective of this, alternatives would be developed so that cards could be accepted again as quickly as possible.

Expired certificate causes problems

Industry circles say that devices do not have to be replaced for the update.

Thus, it is not an issue with an expired certificate that confirms the identity of a computer or other electronic device.

There had been corresponding assumptions in the past few days.

According to industry circles, a hacker attack is not the cause of the problems.

The disruption has been causing trouble in retail for days.

Many customers can only pay for their purchases with cash.

If the giro card (formerly EC card) does not work, it is no longer possible to withdraw cash at the supermarket checkout.

Cashless payments have been given a boost in Germany by the pandemic.

The share of sales from card payments in stationary retail rose from 50.5 percent in 2019 to 58.8 percent last year, according to a study by the Cologne retail research institute EHI published in early May.

Contactless payments, where cards or smartphones are held in front of the terminal, have also become part of everyday life due to the pandemic.

For smaller amounts, it is often not necessary to enter the PIN, so customers do not have to touch the payment terminal.