Help 4.3 need help to unlock network

[Damien74]

Story:
I wiped and reflashed my Galaxy S3 (i9300) to stock rom 4.3 unbranded (XXUGNA8)
Now I learned I would need 4.1 in order to unlock the network but I also learned you can not go back to 4.1 without bricking the phone.

What is my options to unlock this? Anyone know of a cheap, good service?

Additional question:
how do I find out if my ROM really is stock. When I go into download mode I get NO info on KNOX at all. Could this mean I could revert to 4.1 anyhow?

 

[dmcjr22]

In download mode knox shows up as bit warranty but as far as the carrier unlock
have you searched on Xda GS3 19300?

 

[marcus33]

Story:
I wiped and reflashed my Galaxy S3 (i9300) to stock rom 4.3 unbranded (XXUGNA8)
Now I learned I would need 4.1 in order to unlock the network but I also learned you can not go back to 4.1 without bricking the phone.

I'm far from being an expert but as far as I know unlocking the SIM is hardware related and which ROM/Kernal/Firmware you are running shouldn't have any bearing.

What is my options to unlock this? Anyone know of a cheap, good service?

Whereabouts are you?

If you are in the UK you should be able to get an unlock code from the carrier concerned. OFCOM have recently changed the rules on carrier-locked handsets in an effort to stop carriers from holding customers to ransom so it's now possible to get the unlock code without being charged; more info can be found HERE.
I recommend that you investigate all the options before paying for an unlock service, because it might just be possible to get it sorted without having to shell out any dough.

It's well worth doing if you can; as well as the obvious bonus of being able to use whichever network offers the best deal for you, having an unlocked handset will allow you to insert a SIM card from a local network if/when you travel abroad and so avoid roaming charges.

Hope this helps; good luck.