CHICAGO (CBS) — The clock is ticking for some CTA riders who use Ventra cards.

Ventra cards expire after four years, and the first batch issued by the CTA in 2013 expire by the end of the month. Other cards expire as late as 2022, depending on when they were bought. WBBM’s Jim Gudas reports.

The CTA’s Brian Steele said it’s important to register your Ventra card, especially if it is about to expire.

“If you are a registered used of Ventra, it is pretty easy. All you have to do is confirm your address and we will mail you a new card for free. If you are an unregistered user, all you need to do is spend down your balance and purchase a new card at a rail station or online,” he said.

Steele recommends spending any balance on the card before it expires otherwise you risk losing that money.