Dutch metal industry scheme PME failed to pay pensions on time to 40,000 of its 167,000 pensioners last Monday.

It blamed the mishap on an IT glitch, and said the mistake was rectified by the next day.

According to the €47bn pension fund for metalworking and electro-technical engineering, something went wrong when its provider MN sent a batch of payment orders to ING Bank.

“The batch had become stuck somewhere in the system,” said Ellen van Amersfoort, the scheme’s spokeswoman.

As a consequence, the payments weren’t transferred on PME’s fixed payment day, the 24th of the month. This led to phone calls from worried pensioners.

The pension fund said it didn’t know exactly yet what had gone wrong, but emphasised that it would launch a thorough investigation to find the cause, “as this is not allowed to happen again”.

Van Amersfoort, who joined PME five years ago, said she couldn’t remember any similar incident. “We are always very conscientious when it is about payments,” she said.

Michel Cleij, spokesman for MN, which also serves the €72bn metal sector scheme PMT, also said he wasn’t aware of any such payment incidents during the past five years.

“The payment process consists of several checks, ahead of as well as after the payments, with a statement showing whether payments have been successful,” he said.

“Therefore, on Tuesday morning we already knew about the mistake. But around the same time, pensioners started to get in touch with us.”

Problems with benefits payments are rare in the Dutch pensions sector.

Administrative problems are usually about mistakes in granting pension rights, sending mandatory letters for new and leaving participants too late, or mistakes in invoices.

Last year, MN abandoned an innovation project aimed at reducing costs and decreasing the number of administrative errors.