Can I use a sim from another country on an I phone XS dual sim

[Redsim]

I want to upgrade my current phone. I currently live outside of the U.K. and would like to keep my current EE number and then use my foreign sim. Can I do this with an I phone Xs if I buy from EE or do both lines have to be for EE? 

[Dai]

Hi you can if your device is unlocked otherwise both will be locked to EE

[Redsim]

Thanks for your reply. Just to clarify, if I get an XS from EE both numbers will need to be EE lines until I get the phone unlocked? I’m better off getting it unblocked from

apple then? 

[Dai · Accepted solution]

If you buy a sim free device from Apple it comes unlocked to all networks if you buy one from EE you can only unlock it after six months.

yes both lines will need to be EE until it's unlocked.