Question

Why can't I put my T.Mobile prepaid SIM into my phone in Ireland?

  • 14 January 2022
  • 8 replies
  • 81 views

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I recently moved from the US to Ireland.  I have the same phone.  I kept a prepaid account at T-Mobile with the minimum plan to reserve my phone number and to get authorization codes from banks, etc.  Well my idea of swapping out the SIM card to get an authorization code via text is a bust.  No matter what I try.  Is it something with the settings or something to do with being on wifi calling (I have Eir mobile service and broadband here).  Can anyone help please?


8 replies

Userlevel 7
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Some banks and government 2FA services are not possible to receive on prepaid numbers. 

When it comes to WiFi Calling.  Are you using a device purchased from T-Mobile USA?  WiFi Calling settings and how they work can vary greatly by region and carrier.  If you purchased your device on Ireland, it might not be WiFi Calling compatible with T-Mobile. 

Is the device you are using SIM unlocked? 

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Hi thanks for the reply.  I don’t know how to tell if the SIM is unblocked.  I don’t have a contract with T-mobile but a prepay account.  I had a post pay but it was too expensive to maintain just to keep the same phone number.  My phone was purchased outright in the US.

I use wifi calling, should that be unchecked when I try to use the US SIM?  Also, what should I do about the roaming setting?  I’m pretty sure I tried with roaming both on and off and it didn’t seem to make a difference but not sure about wifi calling.

I think my son in law can get authorization codes on his t-mobile prepay plan though, which is how I got the idea to do this but for some reason I can’t.  I guess for now, can you tell me how to unlock my US SIM if that could be it?  What is your best guess that I should try next?

I appreciate your reply!

Userlevel 7
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Buying your phone outright from the US is one thing, but that doesn't guarantee it is compatible with T-Mobile, unless you bought it from T-Mobile or bought a T-Mobile version of the device. 

Try enabling WiFi Calling and connecting to WiFi after putting your device in Airplane Mode. Have you ever used WiFi Calling before?  You might need to contact Customer Care to verify your E911 address is up to date so WiFi Calling can be used.  WiFi Calling also needs to have enough bandwidth through whatever internet it is using to work.  Having at least 20Mbit up and down should be enough for WiFi Calling to work well. 

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Hi - I had T-mobile prepay for about a year or so before I switched to prepay to save money.

I will try airplane mode and see if that works.  I have high speed broadband here so that shouldn’t be an issue.  I do use wifi calling and not sure about how they do it here in Ireland and I think my address is probably linked to my broadband and they use 999 here.  I haven’t been here very long and don’t know much about how things work here yet.

Userlevel 7
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Hi - I had T-mobile prepay for about a year or so before I switched to prepay to save money.

I will try airplane mode and see if that works.  I have high speed broadband here so that shouldn’t be an issue.  I do use wifi calling and not sure about how they do it here in Ireland and I think my address is probably linked to my broadband and they use 999 here.  I haven’t been here very long and don’t know much about how things work here yet.

To use T-Mobile’s WiFi Calling, your E911 address has to be set for your account for a US address where T-Mobile provides service and has an E911 center.  

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ok, i have T-Mobile set up with my US address but while here in Ireland and using the broadband here, I assume i am using wifi calling through that for my irish mobile number.   

Userlevel 7
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You want. to use WiFi Calling on your US purchased mobile for your Ireland carrier?  If so, their WiFi Calling might not. be compatible with your device. 

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Ok - it’s confusing though, because my son in law who has the exact same set up with t-mobile prepaid on a US phone with local wifi is able to switch the SIM cards and get service.  I’m going to try a couple of things.   I’ll check back in. Thanks for your help!

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