Calling all overseas eSIM, WIFI calling and roaming experts for advice for eSIM data + receiving local txt for 2FA

Forums › Travel (planes, train, cruise) › Calling all overseas eSIM, WIFI calling and roaming experts for advice for eSIM data + receiving local txt for 2FA

G1zm0

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#315419 14-Jul-2024 22:53

Hi all, I'm off to Europe soon, and am going to use Airalo(or Holafly) eSIM for data. So that's sweet.

I'm with One NZ here in NZ using an eSIM with them.

I do NOT want to pay their $8 daily roaming charge.

They mention WIFI Calling can be used without incurring daily roaming charge, but are not specific with what phone settings are used to configure.

I need to work out a way to receive texts that relate to two-factor codes that get sent via my One NZ regular SMS phone number (e.g. making a transfer etc).

I think that's possible via the aforementioned WIFI Calling, BUT, how do I turn off or block the cellular connection to ensure I don't get charged the daily roaming fee.

The only thing I can think of is:

Activate flight mode
Turn on One NZ (cellular blocked by flight mode)
Turn on WIFI Calling in One NZ
Activate WIFI in flight mode
In theory the text should come through (can anyone validate?)
Once I have my 2FA, reverse the procedure.
Turn flight mode off, and return to Airalo eSIM
Finish transation.

It sounds messy. I would rather just have the ability to have One NZ Wifi Calling and TEXT enabled, but with the reassurance that the associated Cellular won't kick in and therefore won't get the $8 daily roaming fee.

Ultimately I want:

Use Airalo easily and freely for data
Receive Txts to my NZ number (without incurring daily $8 roaming charge)

Keen to hear from your experiences out there.

Regards,

MaxineN

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#3259548 15-Jul-2024 03:31

Ex One NZ here.

WiFi calling is preferred when roaming so half the steps shouldn't be required, however you will only get dinged whilst you're on the roaming network and you make a call, accept a call, make a text or spin up a data session.

WiFi calling will act as if you are home (in NZ) so yes you'd avoid all charges.

In theory (I haven't and didn't test this), if you had a second handset that accepted eSIM or even a physical euro travel SIM, you could turn that second handset into a 24/7 hotspot device and connect your main handset and be on wifi calling 24/7, avoiding all roaming charges.

Wifi calling has SMS features so yes you can get your texts.

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#3259550 15-Jul-2024 03:39

@G1zm0 5) Yes it is that simple I have used Wi-Fi calling around the globe since 2018 on 2degrees and no issues

Saved a small fortune on roaming charges

G1zm0

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#3259558 15-Jul-2024 08:16

MaxineN: Ex One NZ here.

WiFi calling is preferred when roaming so half the steps shouldn't be required, however you will only get dinged whilst you're on the roaming network and you make a call, accept a call, make a text or spin up a data session.

WiFi calling will act as if you are home (in NZ) so yes you'd avoid all charges.

In theory (I haven't and didn't test this), if you had a second handset that accepted eSIM or even a physical euro travel SIM, you could turn that second handset into a 24/7 hotspot device and connect your main handset and be on wifi calling 24/7, avoiding all roaming charges.

Wifi calling has SMS features so yes you can get your texts.

Thanks for the information, and handy you’re ex one nz!

A couple things still worry me:
- I feel like at any time that there’s no wifi signal that the one nz sim will switch to cellular. So what you’re saying is that even tho it establishes a connection with the foreign cellular provider that as long as no calls are made or received, no texts are made, and no data sessions started then no roaming charge? That’s what I couldn’t find on one nz website, was what was the actual triggers for roaming charge.

On iphone 15, I’m trying to determine settings that effectively disable cellular for my one nz (on esim) but still allow wifi calling and text. Whilst at the same time permitting all the cellular data for the second foreign esim. It seems like I’m not able to turn off ‘mobile data’ and ‘ mobile data roaming’ per esim, that it’s all or nothing.

DjG

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#3259560 15-Jul-2024 08:26

so ive been doing this for years.

Go into setting and the hard set the network on your sim, do not allow automatic network connection, that way it won't be able to find One's network overseas, it then falls back oh hey I have a data connection and uses that over they Airlo 4G data.

ive been doing it with Telstra and OneNZ, its worked perfectly.

MaxineN

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#3259561 15-Jul-2024 08:27

G1zm0:
Thanks for the information, and handy you’re ex one nz!

A couple things still worry me:
- I feel like at any time that there’s no wifi signal that the one nz sim will switch to cellular. So what you’re saying is that even tho it establishes a connection with the foreign cellular provider that as long as no calls are made or received, no texts are made, and no data sessions started then no roaming charge? That’s what I couldn’t find on one nz website, was what was the actual triggers for roaming charge.

On iphone 15, I’m trying to determine settings that effectively disable cellular for my one nz (on esim) but still allow wifi calling and text. Whilst at the same time permitting all the cellular data for the second foreign esim. It seems like I’m not able to turn off ‘mobile data’ and ‘ mobile data roaming’ per esim, that it’s all or nothing.

If you're attached to the roaming cellular network and WiFi drops or you have no WiFi network, if you do any of the following the $8 will come out. You can still be attached to the roaming network and occur no charges unless you do the following, would advise keeping WiFi uptime to the maximum.

You can switch which is the primary for all functions via this article.

Ramblings from a mysterious lady who's into tech. Warning I may often create zingers.

SpartanVXL

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#3259655 15-Jul-2024 11:49

On iPhone simply disable data roaming under Mobile > One Nz esim.

Even if you have not disabled Mobile data > Mobile data switching you will not use any data on One NZ while overseas. Enabling cellular will not charge you, just the things Maxine listed. You can still receive texts for free which solves the 2fa problem.

Only thing iPhone can’t do is wifi calling using a different esim’s data line on the same iPhone. Some androids it is possible, and they may have been a workaround at some point for iphone but it was tricky. Wifi calling of course works normally on any wifi or other phone hotspot.

Edit: ah yes the iphone workaround was to force your home sim to a network it couldn’t connect to, either manual assignment to your home network before leaving or to one at your destination the carrier doesn’t roam on.

With it not able to make a connection overseas it would use the active data connection (intl.esim) for wifi calling. The downside is that you wouldn’t be able to receive texts while it was down?

I tried this in australia but it didn’t really work because One roamed on basically all of the networks there. Calling on hotel wifi and other hotspots was fine and free to aus numbers on my plan.

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djtOtago

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#3259711 15-Jul-2024 12:31

You haven’t mentioned what phone model you have. Not all phones support WIFI calling.

shk292

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#3259984 15-Jul-2024 20:38

Did this recently on my OH's iphone in Europe (with 2d as the NZ provider; I'm with Spark so no overseas wifi calling for me). You can select the travel SIM as preferred for data and have it used to provide "internal" wifi for wifi calling on the NZ SIM, so avoiding any charges. The only times we incurred roaming charges was when the travel SIM lost a data connection (due to coverage), but NZ SIM could make one - then we got pinged $8 per day (fortunately, credit ran out after two days).

I couldn't find a way to disable data roaming on one SIM but not the other on iphone, but as posted above, manually forcing NZ SIM onto 2g only would have that effect.

As far as I know, SMS will still be received over Wifi calling, so you'll receive them regardless of NZ SIM connection

Handle9

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#3260030 15-Jul-2024 22:24

Switch off roaming on your ONE SIM card, enable data on your e-sim and you are done.

Receiving sms overseas is free on ONE (and all other networks AFAIK). I’ve done this for 6 years on skinny. Sending SMS costs 80c unless you are on a roaming plan.

https://one.nz/roaming/useful-tips/

Handle9

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#3260032 15-Jul-2024 22:26

shk292:
Did this recently on my OH's iphone in Europe (with 2d as the NZ provider; I'm with Spark so no overseas wifi calling for me). You can select the travel SIM as preferred for data and have it used to provide "internal" wifi for wifi calling on the NZ SIM, so avoiding any charges. The only times we incurred roaming charges was when the travel SIM lost a data connection (due to coverage), but NZ SIM could make one - then we got pinged $8 per day (fortunately, credit ran out after two days).

I couldn't find a way to disable data roaming on one SIM but not the other on iphone, but as posted above, manually forcing NZ SIM onto 2g only would have that effect.

As far as I know, SMS will still be received over Wifi calling, so you'll receive them regardless of NZ SIM connection

Each active sim has a setting for roaming under settings -> mobile -> sims

You can also specify your data sim and disable mobile data switching.

G1zm0

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#3260521 16-Jul-2024 22:49

djtOtago:
You haven’t mentioned what phone model you have. Not all phones support WIFI calling.

True, iPhone 15 pro max is what I’m using.

Thanks for responses so far everyone, it’s interesting hearing about what people use as a solution.

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shk292

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#3260861 17-Jul-2024 19:33

Handle9:

Each active sim has a setting for roaming under settings -> mobile -> sims

You can also specify your data sim and disable mobile data switching.

Thanks - I didn't know there was a "per SIM" data roaming switch in iphone - there isn't in Android, which is what I'm more used to. I'll know next time

The other observation here is that Spark's failure to permit overseas wifi calling is a real annoyance, given the other networks do this. It's only the huge monthly "databank" that I've built up on Spark that stops me switching to another network

nztim

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#3260896 17-Jul-2024 23:16

If you can get the right One NZ folk involved you can get your SIM barred from connecting to roaming

Then you use your local sim for data and “wifi”
for wifi calling

There is no risk of roaming charges then

A normal CSR can’t do this.

Any views expressed on these forums are my own and don't necessarily reflect those of my employer.

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#3260912 18-Jul-2024 06:29

Roaming can be disabled on Postpaid connections by front line staff from the CRM platform

The only difference between the MSISDN in the core network is SAM=OWN (cant roam) or SAM=ALL (can attach to foreign networks with roaming agreements)