Can you use a Verizon cell phone with cingular plan?

No, you can not use a Verizon provided phone on a Cingular network, unless it is an unlocked phone. Most of cell phones you get with service provider (e.g. Verizon) plans and deals are locked to that particular network and can not be used with another service provider's network unless you unlock the phone.

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Also - Cingular (now AT&T) is a GSM carrier and Verizon Wireless is a CDMA carrier. Each uses different cell phone technology making them incompatable. You can use an AT&T phone and switch it to a go phone once your contract runs out or visa versa. Sometimes pay as you go phones are the best option.