How to set up phone to use Three Go Roam while abroad

Hi all, 
I have some very basic questions about using Three’s Go Roam sim for travel abroad. I got the sim for travel e.g. to USA, mostly so I can use data and texts while I am there for a week or so. 

I understand that when I change over the sim, my phone number will change. But what else happens? Will my phone contacts still be there or do I need to do something to make sure they are saved on the phone? 

Do I have to do some kind of set up admin after I first change the sim? 

What happens to WhatsApp, FB Messenger, Line apps?

What happens when I swap back the sim to my original one, is everything there like it was before? What happens if someone tried to call/text the original number while the sim was not in, is there any notification of missed call or is that gone forever? Does the text appear? How about WhatsApp messages sent to original sim while the sim isn’t inserted, do they appear?

Anything else I need to be careful of?

I would really appreciate some guidance from someone who already does this so I know what to expect. I know I could try swapping over the sim right now to see what happens but I don’t want to lose any of my contacts or messages. 

Thank you in advance for any advice you can provide


  • It's not answering your questions but your situation would be far simpler with a dual-sim phone or even just a second phone.
  • Yes, but that’s not an option for me unfortunately. I’d never even heard of dual sim phones till now.
  • eDicky
    eDicky Posts: 6,572 Forumite
    First Anniversary Name Dropper First Post
    WhatsApp and all other apps, your accounts associated with them, are not affected by changing the SIM. Your contacts list will remain, unless it is only saved on your SIM, which is unlikely these days (you haven't mentioned what kind of phone, but I assume you have a smartphone).
    When someone calls your original number, of course it won't be answered, you may be able to divert incoming calls to your temporary number.
    Incoming texts to the original number will come through when you replace the original SIM, unless they expire first, usually after 7 days(?).
    The Three SIM will have different settings for mobile data connection, but usually these install themselves automatically.
    Nothing changes with the handset when you swap back.

    Evolution, not revolution
  • Thanks eDicky!! Very helpful
  • merchcon55
    merchcon55 Posts: 302 Forumite
    Name Dropper First Anniversary First Post
    I would put the 3 SIM in your phone while still in UK and give it a test - make sure it works properly and that internet configurations are set up properly (as mentioned above this should happen automatically but better to double check).
  • Merchcon55 good idea, now that I know it won’t screw up my phone I will give it a try
  • getmore4less
    getmore4less Posts: 46,882 Forumite
    Name Dropper First Anniversary First Post I've helped Parliament
    Might be too late the cheapest option I found for USA roaming was the £3, 1m, 1GB 3 SIM
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