Can iPhone be unlocked to only specific carriers??

[iMore Question]

HI,
I purchased a new iPhone SE (64GB) that was supposed to be unlocked.
I use a non-US sim card upon activation I get the message:

"The SIM card that you currently have installed in this iPhone is from a carrier that is not supported under the activation policy that is currently assigned by the activation server..."

I contacted the seller and she said that it is only unlocked to SUPPORTED carriers.
Does it even possible?? to be partially unlocked?
I thought it's either being locked to one carrier or being completely unlocked.
she said I should've checked beforehand and that there's no point in trying to unlock it since it is already unlocked.
Any suggestions what to do?!?!?!?

Thanks a lot!

 

[Rob Phillips]

There’s no way to partially unlock an iPhone. The phone is either locked or unlocked. Are you sure that you purchased the correct version of the iPhone SE? There are two different models that support different LTE bands.