If I reset my unlocked iPhone 4 will the unlock go?

Basically I brought this phone over a year now off my friend, it was originally on vodaphone but I unlocked it to EE, however now I want to update my phone to IOS 7 due to this I have to reset my phone completely,(like it's brand new) will my unlock go?

I doubt it but it's worth a shot. I'd try it anyway.

If it has been unlock, then the unlock is permanent. Even if you reset it, restore and update its ios, the unlock will not be remove.

Your unlock will be fine, but be very careful installing iOS 7. You need to get your device's UDID registered on a site like http://www.instantudid.com/ for $5, or you won't be able to activate the beta. In fact, Apple has been known to detect phones that have installed the iOS 7 beta without a registration and permanently disable them. It's not worth the risk.