WhatsApp - What was UP with it...

[ameerat42]

Just FYI as many people use WhatsApp.

Had a frantic call from a friend today, "Help! I can't add people here (in Oz) to Whatsapp and they can't add me"

Friend came around. I saw she had a dual-SIM phone, with BOTH an overseas SIM and also a local SIM installed. The Local SIM was
"active", as she had been making local calls with it. The WhatsApp had been installed using the OS SIM. I had the OS number as
my WhatsApp contact.

Using WhatsApp, I called her and then she called me. Then we sent a msg and a photo. ALL that worked.

It turns out that AS I ONLY had her OS SIM number as my WhatsApp contact for it to work, she had to supply
her other friends who live here THAT OS phone number. We tried that with one of her local friends. - It WORKED.
She (initially frantic friend) is now .

Conclusion: WhatsApp JUST needs a verifiable SIM AND an Internet connection to work. That dual-SIM phone had both.
To the user, it appears quite transparent: WhatsApp works - because of verifiable (in this case OS) SIM; and Local phone calls/SMS
work - because of Local, active SIM. The Internet came from my WiFi at first, then (PRESUMABLY) from her local SIM plan for
the second try using SIM data. Furthermore, her Local SIM number did NOT show up in my WhatsApp contacts list - correctly so.

Aside: I since checked out about using WhatsApp with dual-SIM phones. You CAN (if you really are desperate) install
a second APP that uses lots of your WhatsApp info and "acts like" you've got 2 different WhatsApp accounts. There are
also other, equally arcane means of getting "the same". I didn't bother pursuing them. Immediate problem easily fixed.

[bitsnpieces]

From what I understand, you should be able to sign out and sign back in with a different account, switch accounts essentially, and use her local sim

Much easier compared to trying to do it for Viber...

[ameerat42]

Ta, Bits.
I remember changing SIM in a phone I had with WTSAP installed. It wouldn't work until I told it to use the new number.

I don't think using the OS number will incur any costs - though she'll find out - and her friends can just call her by name
on WTSAP. Meantime she happily returns their calls/msgs, and makes any phone calls she wants - all transparently.