iPhones and International SIMs

BrianBaughn

macrumors 604
Original poster
Feb 13, 2011
6,799
1,107
Baltimore, Maryland
Does anyone know the updated answer to this?:

I'm currently on StraightTalk and I'm traveling to the UK soon and already have a SIM from "Three" that I've used there before with my iPhone 6. I've checked on that SIM and it's still operational. I also have an old, unlocked iPhone 3GS. I'm wondering about getting both phone numbers registered with iMessage so that the iMessage experience will be seamless.

Do I have to take the StraightTalk SIM out of the iPhone 6 and put it in the iPhone 3GS (with SIM adapter) before I leave the USA...or...can I do the swap when I'm in the UK and on wifi?

Thanks in advance.
 

BrianBaughn

macrumors 604
Original poster
Feb 13, 2011
6,799
1,107
Baltimore, Maryland
Here's what I did...

Back in the USA I put my StraightTalk SIM into my 3GS and registered iMessage. Turned the 3GS off and put the StraightTalk SIM back into the iPhone 6. When I got to the UK I put the UK 3 SIM into my 6 and turned that on and registered iMessage. Then I put the StraightTalk SIM into the 3GS and turned it on.

That trick didn't work! I can't receive or send iMessages via my ST number even though the US number originally showed in Settings>Messages.

If I had left the 3GS, turned on, back in the US with ST SIM this would probably work.
 

nicho

macrumors 68040
Feb 15, 2008
3,244
1,932
Here's what I did...

Back in the USA I put my StraightTalk SIM into my 3GS and registered iMessage. Turned the 3GS off and put the StraightTalk SIM back into the iPhone 6. When I got to the UK I put the UK 3 SIM into my 6 and turned that on and registered iMessage. Then I put the StraightTalk SIM into the 3GS and turned it on.

That trick didn't work! I can't receive or send iMessages via my ST number even though the US number originally showed in Settings>Messages.

If I had left the 3GS, turned on, back in the US with ST SIM this would probably work.
Is your StraightTalk sim card functioning in the 3GS?
 

nicho

macrumors 68040
Feb 15, 2008
3,244
1,932
No. It can't.
Then yeah, thats your issue unfortunately, it has no way of activating imessage for your US number. A lesson for the future!

Do you have the option to turn on international roaming on your phone plan? You need a phone signal of some kind to be able to activate imessage.
 

elf69

macrumors 68020
Jun 2, 2016
2,322
482
Cornwall UK
my fiancee used her imessage email in imessage and not her number.

her iphone SE on three and her ipad pro on EE both get same messages as linked to email not number.
But then I an her only contact lol.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.