ING made the credit card details invisible to all its customers on Friday, because some customers could see the data of others in their app.

But later in the day, the shortcoming was remedied by an update of the systems.

Customers could see the name and the first and last four digits of the credit card number of other people, an ING spokesperson tells

"We are very sorry that this is happening," she explains.

At first it appeared to be the credit card details of one customer, but later on Friday the spokesperson reported that the details of a second customer were also visible to some people.

ING then decided to make all credit card details invisible to everyone, but later reversed it.

By the way, people couldn't do anything with the data and couldn't click on it.

The transactions of the credit card owners were not visible to the said group of customers.

It is not yet clear how the data in the app of some customers has become visible.

A solution is being worked on, the spokesperson said.