What is a non-VoIP number? Definition and line types
The short answer, then how services tell a mobile line from an internet number.
What does "non-VoIP" mean exactly?
VoIP, voice over Internet Protocol, is a technology "that allows you to make voice calls using a broadband Internet connection instead of a regular (or analog) phone line", in the words of the FCC's consumer guide. A VoIP number is a number served that way: Google Voice, TextNow, Skype numbers and most app numbers.
A non-VoIP number is the opposite case: a number attached to a SIM card on a mobile network. Nothing in the word says "real" or "fake"; it describes the line type that databases record for the number.
How do services know the line type?
They query a line-type database at sign-up. Twilio's Lookup service, used by many apps, returns categories such as these:
| Line type | Twilio definition | Typical examples |
|---|---|---|
| mobile | "A mobile number that generally can receive SMS messages." | A SIM card on AT&T, EE, Telekom… |
| fixedVoip | "A virtual phone number associated with a physical device." | Cable or broadband home phone |
| nonFixedVoip | "A virtual phone number obtained online without requiring a physical device." | Google Voice, app numbers |
| landline | A traditional fixed line | Copper home phone |
Definitions quoted from Twilio's documentation, checked 2026-10-18.
In the US and Canada the digits cannot tell you the line type, because VoIP providers have obtained numbers in ordinary area codes since the FCC order 15-70 took effect in January 2016. In much of Europe the range itself tells: Germany's regulator says mobile numbers "may be used exclusively for mobile services", and the UK put VoIP in its own 056 range in 2004.
Why do some services refuse VoIP numbers?
Internet numbers are cheap to create in large quantities, so services that want one account per person treat them as higher risk. Some say so plainly: Microsoft states that "VOIP numbers cannot be added as a way to sign in or get verification codes", Telegram that accounts "can only be connected to a mobile number", and OpenAI that it does not support VoIP or Google Voice numbers.
A mobile line type helps, but it is not a guarantee. Services also limit how often one number may be used (Google says it limits "the number of times a phone number can be used for verification") and refuse numbers already linked to another account.
When is a non-VoIP number the right tool?
- You want to keep your personal number private for an app that requires a phone.
- You test a sign-up flow with real mobile numbers from several countries.
- You sign up from abroad to a service that wants a local mobile.
It is the wrong tool for an account you need to recover in a year, such as your main email or a bank: a single-use number is reassigned after use.
Get a non-VoIP number
From $0.36 per US code; 12 countries.
Frequently asked questions
Is a non-VoIP number a real phone number?
Yes. It is a mobile number on a SIM card, which databases class as "mobile".
Is a prepaid SIM number non-VoIP?
Yes. Prepaid or contract does not matter; what matters is that the number is on a mobile network.
Is a non-VoIP number always accepted?
No. A non-VoIP number is classed as mobile in carrier databases, which most sign-up forms accept, but each service sets its own rules and can still refuse a number. If that happens, cancel the order and the price goes back to your balance.
Sources
- FCC consumer guide on VoIP (copy at the First Circuit library) (checked 2026-10-18)
- Twilio Lookup: Line Type Intelligence (checked 2026-10-18)
- FCC 15-70: direct access to numbers for VoIP providers (checked 2026-10-18)
- Bundesnetzagentur: numbers for mobile services (checked 2026-10-18)
- Ofcom: new voice services statement (056) (checked 2026-10-18)
- Microsoft Support: VoIP numbers and verification codes (checked 2026-10-18)
- Telegram FAQ (checked 2026-10-18)
- Google Help: verify your account (checked 2026-10-18)