Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

joeblow7777

macrumors 604
Original poster
Sep 7, 2010
7,303
9,250
I'm preparing for some international travel and it's actually my first time doing so with a phone not locked to a carrier. As such, I was thinking of getting a local SIM at my destination.

Of course I realize that my phone number will be different, but am I correct in assuming that this shouldn't affect my sending or receiving of iMessages or WhatsApp messages? Is there anything I should know or I need to do, or is it just a matter of swapping SIMs?

Upon Googling, I came across some old discussions where people said they had issues with iMessage in this situation, and had to do things like turn off iMessage, log out of their iCloud account, and log back in, but none of these discussions were more current than 2016. Does anyone here have more recent experience?

(iPhone 8 Plus running iOS 12.3.2)
 
I've had some experience with this (lived abroad in Europe for 2 months).

Your main # changes but iMessages still work. Just make sure they're sent from your email rather than your phone # in settings.

Friends & family might remark upon this so I would let anyone you regularly message know about this in advance.

I didn't regularly use Whatsapp.
 
I've had some experience with this (lived abroad in Europe for 2 months).

Your main # changes but iMessages still work. Just make sure they're sent from your email rather than your phone # in settings.

Friends & family might remark upon this so I would let anyone you regularly message know about this in advance.

I didn't regularly use Whatsapp.

Thank you.
 
  • Like
Reactions: ruslan120
I can comment on the WhatsApp question as I used the app extensively while my wife and I were in Europe last year. Swapping SIM cards should have no impact on your current chats with friends/family. Like others mentioned, your number will change for iMessage, but there should be no impact to WhatsApp. As long as you have data, you'll be able to receive/send messages/media.
 
WhatsApp is fine as long as it's activated with your main number prior to the trip.

The iMessage situation hasn't really changed. It will still switch to the new local SIM number. As mentioned, you could use email as primary.

Personally, the iMessage thing has been kinda hard to enforce when dealing with non-techies unless you've always used your email as primary iMessage contact. I found it easier to just tell people I'm going overseas and to use WhatsApp or Facebook Messenger if they need to contact me asap.
 
Thanks everyone.

One thing I’m not sure about. In settings it shows that I receive and reply to iMessages from both my phone number and my email address (there are checkmarks beside both). New conversations start from my phone number, but I’m not concerned about that, as I just want to be able to maintain contact with current contacts.

I’m able to send and receive iMessages on my wi-fi only iPad, and on my phone when it’s in airplane mode (with only wi-fi) on, so I guess I can assume that my iMessages are working fine independent of my phone number?
 
  • Like
Reactions: Wide opeN
If you replace your primary SIM card with the local SIM, things can go wonky (at least as far as phone numbers + iMessage is concerned). Switching to a local SIM on your iPhone could potentially disable your main phone number in iMessage on the iPad as well. Trying to get it working again while overseas with high latency internet connection? So not fun.

Airplane mode is fine though. It's replacing SIM cards that can cause issues.
 
The worst that may happen is that your contacts will receive messages from the foreign phone number associated with the SIM you buy overseas. If your messages are also associated with your email, you can switch to it as the sender if you don't wish to freak them out or inadvertently get blocked.

Both Messages and WhatsApp will work fine with existing chats otherwise.

I usually go the local SIM route, and give out a Google Voice or other VoIP number that will need only data if anyone wants to call. WhatsApp voice calling is another option.

I'm in Europe now and bought a 30-day Vodafone UK SIM that roams the EU for free, 25GBP for 20GB data, 4G coverage in most spots so far. They've texted bonus offers and added data, so I still have about 20GB available after doing cloud backups of two weeks of photos, maps usage, etc. (~8GB). Also included unlimited texts and 250 voice minutes or something like that. It comes with a UK number and English-speaking customer service if needed. Tethering, too.

Foreign SIMs can also be pre-ordered and delivered prior to a trip, from Amazon and others, but after some research, I didn't want to go with an MVNO, or a carrier (Three) that had poorer coverage/roaming (3G) in the places I'm visiting, or not valid long enough for the length of my stay. Your needs will vary, so shop around.
 
I'm preparing for some international travel and it's actually my first time doing so with a phone not locked to a carrier. As such, I was thinking of getting a local SIM at my destination.

Of course I realize that my phone number will be different, but am I correct in assuming that this shouldn't affect my sending or receiving of iMessages or WhatsApp messages? Is there anything I should know or I need to do, or is it just a matter of swapping SIMs?

Upon Googling, I came across some old discussions where people said they had issues with iMessage in this situation, and had to do things like turn off iMessage, log out of their iCloud account, and log back in, but none of these discussions were more current than 2016. Does anyone here have more recent experience?

(iPhone 8 Plus running iOS 12.3.2)
My wife just came back from 1 mo in Europe. She also swapped out sims in her iPhone. We communicated mostly using iMessage & FT completely free over WiFi. Turn your data settings to off to avoid exorbitant roaming charges.
 
  • Like
Reactions: Wide opeN
My wife just came back from 1 mo in Europe. She also swapped out sims in her iPhone. We communicated mostly using iMessage & FT completely free over WiFi. Turn your data settings to off to avoid exorbitant roaming charges.

But isn’t the point of getting a local sim so that you can continue to use data?

Having travelled with carrier locked phones in the past, I’m familiar with turning off data and surviving on (crappy) hotel and public wifi.
 
I do this regularly. It used to be confusing but I've pretty much got the hang of it now.

Whatsapp works fine - it'll ask you if you want to change numbers and you just answer No. it does that with me each time I go roaming even without changing sim cards, which is odd.

I've just about got everyone (who uses them regularly) to use my iCloud email address for iMessage and FaceTime but usually they just hit "reply" to whatever I last used to contact them. Change "start new conversations from" in settings to your icloud email address and start new conversations with people. This may be fixed in iOS13 (I've not tested it) but at the moment that will cause a new conversation their end too. At least in future, so long as they start using that email address as your contact, you can change numbers as many times as you like with no impact.

Or just iMessage everyone your new number once you put the SIM card in and let them worry about it.

My only issue is that my Mum has finally worked out to send iMessages and FaceTimes to my icloud email address but now she sends emails to it too. And I don't use it for emails. I really wish Apple would realise that iMessage and FaceTime don't really need to be associated with phone numbers at all, and also that an iCloud ID should not be an email address.
 
  • Like
Reactions: Wide opeN
  • iOS will ask if you want to change your phone number - tap yes
  • WhatsApp will ask if you want to change your phone number - tap no

It may take 0-24 hours before you can send iMessages correctly. During this time, it may default to SMS. iOS needs to ping the server with your new local number before iMessage works.
 
But isn’t the point of getting a local sim so that you can continue to use data?

Having travelled with carrier locked phones in the past, I’m familiar with turning off data and surviving on (crappy) hotel and public wifi.
I keep my old iPhone as spare when I upgrade and use that for the local SIM. Way cheaper for data plus I often need it for local contacts anyway. By using a separate device, I can continue receiving iMessages and SMS sent to my main number seamlessly (I've needed the latter for 2FA for banking). :p

Mind, people that *need* to be able to contact me when I'm on vacation are informed to send messages via WhatsApp. I'd even setup the app on their phones if they don't already have it installed.
 
I keep my old iPhone as spare when I upgrade and use that for the local SIM. Way cheaper for data plus I often need it for local contacts anyway. By using a separate device, I can continue receiving iMessages and SMS sent to my main number seamlessly (I've needed the latter for 2FA for banking).
That's a good point. Receiving old fashioned SMS's to the old number. Plus, as you say, if you use the same phone then when Apple's servers activate iMessage against the new number, it knows it's the same phone and kills the old one.

I assume the new phones with their dual-sim capabilities solve all these issues. With my 6S, I'm still at the "anyone got a paper-clip?" stage of sim-swapping technology.
 
I assume the new phones with their dual-sim capabilities solve all these issues. With my 6S, I'm still at the "anyone got a paper-clip?" stage of sim-swapping technology.
Yep, they should. I'm curious what the lock status is on eSIM-capable iPhones purchased through carriers. They often have deals not available if buying from Apple.
 
Whatsapp: no issues as it is linked to your original phone number. However, Whatsapp may ask to re-verify your number since it detects a new SIM. Do not do this as this will switch your number to the new foreign one.

iMessage: Normally, you could just swap SIM, and iMessage will automatically activate using the new foreign number. Make sure you pick an email as your caller ID though so people can know it's you. When you arrive back at your home country, simply swap SIM again and iMessage will reactivate using your original number. At least that's what ideally should happen. Sometimes though, it won't. I have some countries' SIMs that just won't activate with iMessage, so my iMessage "number" is stuck with the previous SIM. Thus using email as your "start new conversation from" is a better route, ignoring the SIM number you put in.
 
  • Like
Reactions: Wide opeN
Whatsapp: no issues as it is linked to your original phone number. However, Whatsapp may ask to re-verify your number since it detects a new SIM. Do not do this as this will switch your number to the new foreign one.

iMessage: Normally, you could just swap SIM, and iMessage will automatically activate using the new foreign number. Make sure you pick an email as your caller ID though so people can know it's you. When you arrive back at your home country, simply swap SIM again and iMessage will reactivate using your original number. At least that's what ideally should happen. Sometimes though, it won't. I have some countries' SIMs that just won't activate with iMessage, so my iMessage "number" is stuck with the previous SIM. Thus using email as your "start new conversation from" is a better route, ignoring the SIM number you put in.

Does it matter if I don’t start any new conversations?
 
You'd only need to do that if the conversation won't switch to your email.

Simply uncheck your number when you get where you're going under iMessage. Problem solved.
I never thought of that! I would deliberately start new conversations with people whereas your method makes that happen automatically.

The issue with all this is that people then save my iCloud email address in their contacts (so that it identified the messages and facetime calls as coming from me) and then start using it as my email address. I guess that's fine for most people, but my iCloud email address isn't the one I use for actual emails. I deliberately kept it separate as I may iMessage and/or FaceTime people that I've no wish to share my email address with! :)
 
  • Like
Reactions: Wide opeN
Well guys, in spite of all your help, I think I messed up! :D

I'm at my destination and I visited a local carrier store today. I purchased a prepaid SIM with 2GB of data, but no call minutes or SMS texting. This suits my needs just fine.

The lady offered to install and activate the SIM and I let her. Everything seemed fine until I tested out iMessage later.
In settings, under iMessage it says "Waiting for Activation". I believe that it's trying to activate through my usual number.

When I tap on Send & Receive, under "You can receive iMessages to and reply from", first is listed my usual phone number, but it is greyed out and there's a perpetual loading circle going around beside it. I can't seem to remove it. Under it are two email addresses associated with my Apple account, both with check marks beside them.

Under "Start New Conversations from" are the email addresses but know phone number.

If anyone can help me sort this out that's great, but the good news is that anyone who is likely to need to reach me while I'm away has other means of doing so, so this is mainly academic at this point, but it is bugging me.
 
iMessage requires SMS for activation. Iirc, when I was in the Philippines, it actually needed to send an international SMS (to Singapore?). Even then, I found it problematic.

That's why I just use WhatsApp or FB Messenger. If I needed iMessage, I'll do it on the iPad (which was unaffected by iMessage activation shenanigans).
 
  • Like
Reactions: adrianlondon
I purchased a prepaid SIM with 2GB of data, but no call minutes or SMS texting. This suits my needs just fine.
That's the problem. iMessage Activation happens through an international text message. From India, it goes to a +44 number in UK.
You will need to add sms in your plan to get it activated.
 
iMessage requires SMS for activation. Iirc, when I was in the Philippines, it actually needed to send an international SMS (to Singapore?). Even then, I found it problematic.

That's why I just use WhatsApp or FB Messenger. If I needed iMessage, I'll do it on the iPad (which was unaffected by iMessage activation shenanigans).

That's the problem. iMessage Activation happens through an international text message. From India, it goes to a +44 number in UK.
You will need to add sms in your plan to get it activated.

I see. I thought that was likely the problem. Oh well. At least I have a better understanding of how it works for next time. I can get by with 3rd party messaging apps this time. Thanks again!
 
  • Like
Reactions: adrianlondon
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.