Using eSim and Wifi calling for International Travel

eSim/wifi calling solution for travel

This may be duck soup to many, if not most, but it was an eye opener to me.

Needed a solution for upcoming trip from Australia to US for extended stay. One issue is text based 2factor messages to Telstra prepaid phone number. In some cases, no alternative method of authentication is offered, meaning I could not log in while overseas.

Bottom Line - Using wifi calling for my Telstra prepaid number and esim for US Mint Mobile phone plan, will have mobile coverage in US including data, and maintain Telstra connectivity when on wifi for total of US$45 for 3 months (actually 6 months with Black Friday offer) in US and no additional cost on Telstra.

Rich Demuro provided the answer in a round about way without providing details.

While in Australia, installed Mint Mobile app on iPhone. Accepted offer to try Mint Mobile (MM) for 7 day free trial. Installed MM eSim. Here is where it gets tricky. MM app tried to activate eSim, but no T-Mobile network available, which it needs to activate. Went into Settings/Mobile/‘MM eSim’ and turned on “Wifi Calling”. eSim was activated. Signed up for 7 day trial.

Tested it out. Australian Telstra Prepaid selected for Mobile Data and Default Voice Line. MM eSim selected “On”. While on wifi, calls and messages to MM US number come to phone immediately. If not on wifi, messages come to phone as soon as I connect to wifi.

Have now signed up for 6 month MM plan at 50% off Black Friday price. Setup MM Voice Mail and tested it out. Called MM number and left a message. Turned on MM eSim and while on wifi, could access voicemail.

After landing in US, will switch to MM eSim as Default Voice Line and Mobile Data, with Telstra prepaid “On”, “Roaming Off” and Wifi Calling “On”.

Backup method in place too. Another Rich Demuro idea presented when he filled in for Lea several years ago. Using Airalo app and US data only eSim for backup data connection if necessary. That providers access to Skype for phone if needed.

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I had this issue on our last US trip as my UK mobile now doesn’t cover the US from my plan’s minutes/data. They charge you £5/day which soon adds up if you are there for a while with a few SIMs.

So I prepaid for an international data-only eSIM, thinking I could leave roaming off and pick up UK calls and SMS using WiFi calling.

Problem was the International eSIM needed roaming turned on to work, and I didn’t trust the UK provider not to use any data (and trigger the £5 charge) so I just turned off my UK SIM completely in the end.

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It will be interesting to see how my solution works when in US, but it os working great here. Since both plans are Prepaid, there can be no additional charges.

I have always avoided post-paid phone plans. Started with a mid-range prepaid monthly plan, and kept reducing it as I never reached the data limit. Finally transitioned to annual plan that costs $300/year and in 10 years, never ran out of data.


Family/friends visiting us from Czech Republic always use TMO while traveling across USA. They download the free TMO esim standalone ios app before leaving Praha & then once they arrive USA they open it, register and purchase a plan. Prices, coverage and speed are very good and much better than Mint esim cause Mint texting can cause so many issue

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