if I unlock iPhone for use with a different carrier will my phone be vulnerable

If I unlock iPhone to use with a different carrier, will my phone be vulnerable

No, assuming you are using normal security precautions that you have always been using.

To clarify, you don't unlock your phone. Your current carrier does. The only reason to do this would be if you want to switch your cell service from one carrier to another.

For example, your carrier is now Verizon. You want to switch to AT&T.

To do that, you must contact Verizon and have them remove the carrier lock on your phone. When that is done, you call AT&T and ask them to set up service on the phone. The phone will then be locked to AT&T. Instead of a monthly bill from Verizon, you will now get a monthly bill from AT&T.

Your phone is safe as long as you are using a passcode and you don't give your Apple ID and Password to someone else. Same security measures that you have always been using.

should I just get a new phone?

Probably no reason to do that unless the phone is very old, and it cannot run newer iOS versions.

Bob Timmons wrote:

For example, your carrier is now Verizon. You want to switch to AT&T.

To do that, you must contact Verizon and have them remove the carrier lock on your phone. When that is done, you call AT&T and ask them to set up service on the phone. The phone will then be locked to AT&T.

Not correct. Once a phone is unlocked, it is unlocked for all carriers. So after using it on AT&T you could switch it to T-Mobile without having to ask AT&T to unlock it. Or any of hundreds of carriers around the world.

Hmm. Wonder why my phone shows locked to AT&T after I switched from another carrier. So, I can just ignore that if I want to switch next year some time?

It should not show locked to AT&T. Where are you looking? Settings/General/About: Carrier Lock? Did you finance it with AT&T?

Phone was paid off before switch to AT&T, but did sign up for a 1 year deal on service.

Maybe that is why the lock appears at Settings/General/About: Carrier Lock