Ikea has been bitten by the millennium bug, forcing its store card customers to endure another two weeks of payment problems at tills in UK stores.

The store card of the Swedish home furnishing giant is not being accepted by computer systems because of a Year 2000 problem, causing card transactions to be wrongly rejected for over-shooting the expiry date 12/99.

Ikea has admitted that the problem will not be resolved until the end of this month.

Store card holder Jacqueline Nieber tried to use her card at Ikea's Brent Park outlet last Sunday.

"The card was rejected and my first thought was I had forgotten to pay the bill, but then the cashier told me it was a millennium bug problem," she said. "Ikea head office had to authorise the payment over the phone so it could be coded in manually.

"There were queues and queues of people in the store and it took six times as long to pay," she added.

Jens Rom, managing director for Ikea's card programme in the UK, claimed that he had received only one complaint about the cards and that the problem was not the Y2K bug, it was just "millennium-related".

Rom said Ikea cards are not embossed with an expiry date because every card transaction is authorised online. However, at the time of the card's launch in 1994, software in the tills required an expiry date for cards to be accepted and 12/99 was coded on the magnetic strip in every card.

"If it hadn't been for Y2K, we could have put a much later date in, but our account system would not accept dates beyond Y2K," he admitted.

Ian Hugo, assistant director of millennium bug watchdog Taskforce 2000, said: "This problem comes in the Y2K sphere. '12/99' was the latest date to be used on the card, as December 1999 had special meaning as the end of time."

In a recent report, analyst GartnerGroup said that despite no apparent major disasters, "the rollover has not been near as smooth as most governments and the media state".

"Only a few vendors sites have reported issues and related work-arounds," said Andrea Di Maio, Gartner's Y2K Strategies director. "This confirms that investments to address the Y2K date change were essential for organisations to continue operating."

Last year, Ikea realised that a fix to the till software was necessary to make it ignore the expiry date, but the problem arose when the test environment failed to mirror the live environment.

"We realised they were not 100 per cent compatible when we tried to implement the fix in stores before Y2K," said Rom. "We had a Y2K freeze and knew it would be impossible to get people into work on the fix before then, and so had to do it after the date. It has been inconvenient and has cost man hours."

Cashiers have been notified to "force through" transactions that give a till message 'card expired', but "you can't make sure every cashier knows", he added.