Explainer
What a non-VoIP number means and why you keep being asked for one
“Please enter a non-VoIP number” means: give us a number allocated to a mobile carrier, not one issued by an internet telephony provider.
The distinction the platform is drawing
Every number belongs to an allocated block with a recorded type — mobile, landline, or VoIP. Platforms look that type up and act on it. Non-VoIP simply means the lookup must come back as a mobile line.
Why your existing number failed
Second-number apps, softphone services and most free number services issue VoIP ranges. They are convenient and they are precisely what the filter is built to catch.
What satisfies the requirement
A number in a mobile range on a real carrier — which is what SwiftSMS supplies, and the reason its numbers pass checks that free alternatives do not.
