I solve this problem by not leaving NZ.

littlehead:

 

Spark also do not support Wi-Fi calling while outside NZ, so even if they do allow blocking roaming on prepay it may not work. I know you can block it on postpaid.

 

From their website:

 

 

Could always VPN through your home network (assuming it's blocking by IP address and not some latency issue).

Yes, Spark can bar a mobile from roaming no issues at all, but correct, SMS over Wifi is currently not supported and Voice over Wifi is not available when overseas.

andyb:

 

Yes, Spark can bar a mobile from roaming no issues at all, but correct, SMS over Wifi is currently not supported and Voice over Wifi is not available when overseas.

 

Is the lack of VoWiFi overseas a technical problem or a commercial decision?  Seems strange that 2Degrees have had this for years, and yet our biggest Telco is unable/unwilling to provide

What's the difference from a technical perspective of where the origin of an IP connection terminating at Spark is?

The prepaid barring on One, stops calls/sms/data from being made but doesn't stop the SIM from attaching to any of the AU networks (Telstra, Voda, Optus). This stopped iOS from using wifi calling over mobile data. 
I did investigate 2 Degrees - they had something very similar but couldn't make it work consistently. 

In the end, I've worked on a compromise - reattach the account to my business pool plan and get roaming barred properly. Not ideal but I guess it does give me an alternative in NZ (Telstras per day roaming is a very sad 1GB). 

These issues a huge concern for me also. Not sure if the confusion is in the market, or just in my head, perhaps fuelled by a lack of clear information and guidelines. Just had a three-month saga overseas in South Africa, using three services on a dual-sim iPhone 13 (One NZ eSim plus a second physical local SA Vodacom sim, plus WhattsApp)

1.) NZ on-account sim: I closed this line down while in SA, as I was afraid the always-on $8 a day roaming would cost me a fortune. Not sure if my fear was justified, but this caused me major problems at three points in my journey, two involving phone verification with my NZ bank and credit card company, and one involving the same with Apple 2-factor verification, which is linked to the same number. It would have made my life much easier if this had offered an ability to “text roam only” as SA Vodacom allows their sims outside that country. The issue with Apple was thorny, as one needs to have an SA Apple ID for some local apps you need (such as local rideshare apps and the Eskom power shutdown schedules) and I could at some point not get back to the NZ App Store without phone verification …

2.) Local SA pay-as-you go Vodacom Sim: Good for those rare calls to people who don’t use WhattsApp, but mainly for data to use WhattsApp when outside Wi-Fi range. SA has a confusing array of pay-as-you-go plans available, and you can only buy data month-to-month, with no carryover. Turned out the trick is to only buy airtime (which DOES carry over month to month), and to convert that to data as needed using the internal Vodacom menu system. No need to keep buying vouchers from cafes. A nice feature on SA Vodacom is that you can switch on “text roaming only” when outside the country, a feature I wish One NZ had! 

3.) WhattsApp: This worked fantastically, although I had some problems getting my phone to save new SA contacts, possibly to do with my +64 WhattsApp number, and vice versa. Still not fathomed that issue, but perhaps a fight between Apple and WhattsApp-owner Meta to protect Apple’s FaceTime service. Worth noting that all South Africans use WhattsApp, even many businesses and most banks, who use WhattsApp business accounts, some with advanced features. Very unlike the stigma NZ businesses still attach to its use. 

==> MY ISSUE: At one point I could not buy a local domestic plane ticket as I could not receive the credit card verification text. Instead of biting the bullet and switching on One’s $8 a day roaming, I foolishly called the credit card firm back in NZ and allowed them to switch me to E-mail verification, which unbeknownst to me caused me major headaches further down the track. Part of my trip was to buy property, and when it came to payment, it turned out you cannot create an overseas beneficiary without phone verification, and that it takes 7 days to reconnect the latter. A major problem that took extreme workarounds, as telegraphic bank transfers from NZ to SA are not allowed without couriered original documents if the request originates in SA.

==> MY REQUEST: I am heading back to SA for a much longer period in November, and need both to remain in contact with my NZ bank, IRD and RealMe via my NZ +64 sim, and also need a local sim for local calls and affordable local data. I most definitely will switch my One NZ number to pay as you go to get away from the $8 a day roaming, BUT does anyone have views on what system is the best to keep NZ texts alive and affordable when outside NZ? I may be away for more than two years this time, so critical I pick a system that just works! Also needs to be affordable, and easy for me to pay from over there. And no room for error over there. Being stuck without money, bank access or phone access can have quite severe repercussions!

I don't believe one.nz on-account SIM Roaming charges apply until you answer a call, send a text or consumed data.  At least that was my experience pre-Covid.

The way how I did it was by turning off Data Roaming on the phone, never replying to txt or answering calls.  Someone said rejecting a call may trigger roaming charges too so I never tried.

article:

 

These issues a huge concern for me also. Not sure if the confusion is in the market, or just in my head, perhaps fuelled by a lack of clear information and guidelines. Just had a three-month saga overseas in South Africa, using three services on a dual-sim iPhone 13 (One NZ eSim plus a second physical local SA Vodacom sim, plus WhattsApp)

 

1.) NZ on-account sim: I closed this line down while in SA, as I was afraid the always-on $8 a day roaming would cost me a fortune. Not sure if my fear was justified, but this caused me major problems at three points in my journey, two involving phone verification with my NZ bank and credit card company, and one involving the same with Apple 2-factor verification, which is linked to the same number. It would have made my life much easier if this had offered an ability to “text roam only” as SA Vodacom allows their sims outside that country. 

 

2.) Local SA pay-as-you go Vodacom Sim: Good for those rare calls to people who don’t use WhattsApp, but mainly for data to use WhattsApp when outside Wi-Fi range. SA has a confusing array of pay-as-you-go plans available, and you can only buy data month-to-month, with no carryover. Turned out the trick is to only buy airtime, and to convert that to data as needed using the internal VF menu system. No need to keep buying vouchers from cafes. A nice feature on SA VF is that you can switch on “text roaming only” when outside the country, a feature I wish One NZ had! 

 

3.) WhattsApp: This worked fantastically, although I had some problems getting my phone to save new SA contacts, possibly to do with my +64 WhattsApp number, and vice versa. Still not fathomed that issue, but perhaps a fight between Apple and WhattsApp-owner Meta to protect Apple’s FaceTime service. Worth noting that all South Africans use WhattsApp, even many businesses and most banks, who use WhattsApp business accounts, some with advanced features. Very unlike the stigma NZ businesses still attach to its use. 

 

==> MY ISSUE: At one point I could not buy a local domestic plane ticket as I could not receive the credit card verification text. Instead of biting the bullet and switching on One’s $8 a day roaming, I foolishly called the credit card firm back in NZ and allowed them to switch me to E-mail verification, which unbeknownst to me caused me major headaches further down the track. Part of my trip was to buy property, and when it came to payment, it turned out you cannot create an overseas beneficiary without phone verification, and that it takes 7 days to reconnect the latter. A major problem that took extreme workarounds, as telegraphic bank transfers from NZ to SA are not allowed without couriered original documents if the request originates in SA.

 

==> MY REQUEST: I am heading back to SA for a much longer period in November, and need both to remain in contact with my NZ bank, IRD and RealMe via my NZ +64 sim, and also need a local sim for local calls and affordable local data. I most definitely will switch my One NZ number to pay as you go to get away from the $8 a day roaming, BUT does anyone have views on what system is the best to keep NZ texts alive and affordable when outside NZ? I may be away for more than two years this time, so critical I pick a system that just works! Also needs to be affordable, and easy for me to pay from over there 

 

 

 

Thanks … that is a great help! 

I was wondering if that is a possibility. It would really help if the system was not as clear as mud. So much guesswork involved. And they are really cutting off their noses to spite their faces  by not making these things super affordable, basically pushing all users to WhattsApp by default!