[ossguy]

That's how https://jmp.chat/ works, and you can make your phone number as arbitrarily secure as you want with JMP.

Any port-out requests are handled manually - you are contacted by a human to ensure that you made the request. You can ask them to put a verification code on file for you to confirm when this happens if you're concerned about the security of your XMPP account (which itself could use whatever kind of authentication scheme you like).

[juskrey]

Good luck trying to use VOIP numbers with US banks these days

[ossguy]

In practice it seems to work fine with the banks I've tried. There may be one or two that don't accept numbers whose type is listed as "voip", but they are in the minority.

There is also work being done to update the type field of JMP numbers so they appear as "mobile" instead.

[juskrey]

Note this is a pretty recent movement in banking security, several months or so. E.g. Wells Fargo did work previous autumn, not anymore. More can be googled.

Type field is interesting. Not sure this can pass the radars for too long though.