The glitch was spotted on Tuesday when tickets for the event went on sale.
According to the Associated Press fans with Visa cards that expire before the end of August weren’t able to complete their orders. Visa–an Olympic sponsor–is the only credit card that can be used to buy tickets for the 2012 event.
“It is an issue with Visa rather than the website or our systems,” officials with London 2012 told the Associated Press
Officials have been urging fans not to buy tickets for the Olympic Games so far ahead of time. The deadline is April 26, and there are no promotions or discounts when buying the tickets early.