You can flash a Verizon Note 3 to Sprint and you can flash a Sprint Note 3 to Verizon. It has nothing to do with carrier locked/unlocked phones in CDMA. Flashing is done through CDMA flashing tools such as DFS. Either direction you go, you will only get voice, SMS, MMS, and 3G data speeds. No LTE. It is best that you just trade your Sprint Note 3 for a Verizon Note 3 if you've never done a CDMA phone flash before and/or if you want to use LTE.