Newbie question for Cell phone security

[Laptop Surgeon]

I have a couple of oldies LG 4010, Moto V220 i like unlocked.

If i have someone unlock it, is there a chance that the electronic serial number can be cloned and used on another phone, thereby causing me problems down the road?

If i bring the phone to the guy with the gear to unlock, would i need to leave the unit with the tech for a while, or can it be done in minutes?

[audit13]

GSM providers (Fido, Rogers, T-Mobile) use the sim card for authentication. Cloning your electronic serial number would not provide any real benefit without your sim.

Unlocking a phone should only take a few minutes if the person knows what they are doing.