A mandate by the FCC could mean you need to get a new cell phone, and if you don't, you could be penalized.

In 2001, the FCC mandated that all wireless users have a cell phone equipped with GPS technology by the end of 2005.

The move enables emergency dispatchers to locate cellular callers.

This affects U.S. Cellular customers with phones more than 3 years old and the deadline to upgrade is April 29th.

A spokesman for U.S. Cellular says customers don't have to change their phone plans, but they may be charged a fee in the future if they don't upgrade their phone.

Jay Ellison, US Cellular COO says while customers don't haev to change their phone plans, they could be charged a fee in the future if phones aren't upgraded. " What we have said is there may be a surcharge in the future because with the older technology, we're not going to be able to do a number of things that may be required."

If the customers have been with U.S. Cellular more than three years, they won't be required to have a new contract and phones are being offered at prices typically reserved for new customers.

Other wireless companies are offering discounts as incentive for customers to switch phones.