3 min read
The usual reasons
- The app blocks VoIP numbers and TextNow numbers are VoIP
- The number was recycled and is already linked to someone else’s account
- The app sends codes from a short code that the VoIP network doesn’t deliver
What the error looks like
Sometimes “Invalid phone number” or “This number can’t be used”. Often nothing at all: the app says the code was sent, and it never arrives.
What to do
- Try email or Google/Apple sign-in if the app offers it
- Use a mobile number instead: a temporary one from CoveSMS, balance back if no code comes
- Don’t retry the same number many times: apps start rate-limiting you