AT&T announced at the start of 2015 that it’d begin shutting down Cricket’s CDMA network in March, and six months later, the shutdown will be complete.

Cricket says that it will officially shut down its CDMA network tomorrow, September 15. The prepaid operator still has a “few” customers on its old CDMA service that are located in California “and a few additional locations,” but if they’re still on CDMA after tomorrow’s shutdown, they’ll have no service.

Cricket has a page on its website that’s dedicated to explaining the switch from CDMA to GSM and how they can move to the new network, whether that be through an iPhone SIM swap or a feature phone trade-in that’ll get customers a GSM phone that’s equivalent to their CDMA feature phone. While some Cricket folks may not have been able to switch to a GSM device or aren’t aware of the change, they’ll certainly be motivated to make the switch if they lose service.