[mindslight]

Note that one problem with voip providers is the numbers/lines often won't be recognized as valid by snake oil 2FA and the like. So porting to a voip provider only works if your goal is receiving SMS/calls from actual humans or just parking the number for later. But if you're doing it to avoid having to change your number for every service that has an SMS nagwall, it likely won't work.

You can get a modem that will do SMS (eg a Sierra Wireless card), but I don't know if/how they do voice.

Also, I'd shy away from the RPi based on the unreliability of SD cards. It would/will be pretty annoying for your host to go down and you have to travel back to fix it. I suppose if your friend is halfway handy you could keep an image of the machine as installed. Or even take new images remotely (rsync from the raw device a few times in a row?). If the root filesytem goes wonky, have your friend pull the SD card and reimage it.

[EVa5I7bHFq9mnYK]

I've been using a voip number for all my sms 2fa needs for the last 5 years while living abroad. I have a dozen banks and other financial institutions plus the irs happily accepting it. Some companies, like openai, wont accept it, for those I just buy single use SMS numbers.

[mindslight]

I've had problems with a bunch of places, so it's at least YMMV then. And I'd be wary of transferring an existing number in (as opposed to getting a new voip number and then setting it up).

I'm sure specific services are hit or miss - there really shouldn't be a problem sending SMS to whatever number a user enters, but paternalistic snake oil salesmen gonna be paternalistic.

I've had the least difficulty with Google Voice (I believe it's impossible to tell "Google Voice" usage from bona fide Fi usage where it's really the users' only phone number). Voip.ms has worked very little for me, to the point of that I don't even try it. Heck I even used a voip.ms number for some online classifieds, and another person using Comcast/Xfinity mobile couldn't text me. I'm not saying this as a slight against Voip.ms itself, from what I've gathered most voip providers will be treated similarly.

One of these days when I get around to it I plan on setting up a wireless modem on a $3/mo paygo plan for my SMS nag needs. With a script that automatically brings the number as close to my paste buffer as possible.

What single use SMS service do you use? I haven't really investigated those.

[Spooky23]

Some services can definitely detect Google Voice. Chase bank won’t send SMS to voice.

[EVa5I7bHFq9mnYK]

I have a Chase account, they send 2fa texts to my voip number ok, but it's not Google Voice, it's another service.

[singpolyma3]

> I believe it's impossible to tell "Google Voice" usage from bona fide Fi usage where it's really the users' only phone number

These are definitely distinguishable, and some auth service treat them differently. Google Voice numbers come from a different carrier (the one named Bandwidth) than most Fi numbers.

[rsync]

"One of these days when I get around to it I plan on setting up a wireless modem on a $3/mo paygo plan for my SMS nag needs. With a script that automatically brings the number as close to my paste buffer as possible."

This is called a "2FA Mule":

https://kozubik.com/items/2famule/

"A 2FA Mule is a mobile phone configured to forward SMS 2FA codes via email."

[davchana]

I use something similar. A dedicated app makes a POST request to my Google Apps Script as soon as any sms arrives at my second phone. That script sends it in a Telegram Bot Chat to all of my devices.

[InvaderFizz]

I use a RedPocket (GSMA Flavor) $60/year for my resume and 2FA number as an eSIM.

I turn it on when needed, which is almost never. When not job searching, the voicemail plays the classic "this line has been disconnected" tones and message on repeat for two minutes. WiFi calling means I can use it anywhere I have WiFi.

I get incredibly few spam calls using this strategy.

[agwa]

There are two different reasons companies ask for your phone number, and it's worth distinguishing between them:

The first is for sending a verification code during signup to prevent spammy/abusive signups. In my experience, this is the least likely to work with VoIP numbers because companies often intentionally block VoIP numbers.

The second is for sending 2FA codes during login. My experience with this has been much better. AFAICT, companies do not intentionally block VoIP numbers for this use case. When SMS does fail, there is almost always an option to send the code by voice call, and this is always 100% reliable.

I also have some experience with using a modem with a SIM card to receive SMS. I've used two different models of modem (not Sierra Wireless) and both have been very flaky, often locking up and requiring a power cycle, or having hours-long delays when receiving SMS. I would not call this approach a panacea.