VoIP number
Definition
A phone number that runs over the internet rather than a mobile carrier's SIM, such as Google Voice or TextNow lines.
VoIP number, explained
A VoIP (Voice over Internet Protocol) number routes calls and texts over the internet instead of through a SIM on a mobile network. Google Voice, TextNow and most burner or second-line apps use VoIP numbers. They are cheap or free to create, which is exactly why many platforms block them during sign-up: a line type lookup flags the number as VoIP and the app refuses it or never sends the code. VoIP numbers can still be great for everyday calls and texts, and some services accept them for recovery. For verification on stricter apps, a mobile number is usually required.
Related terms
Non-VoIP number
A phone number issued by a mobile carrier for a SIM, so line type checks report it as mobile rather than VoIP.
Line type lookup
A check that tells an app whether a number is mobile, landline or VoIP, and often which carrier owns it.
Virtual phone number
A phone number used without a physical SIM in your own phone, reached through an app, website or online dashboard.
Where you'll meet this term
Non-VoIP vs VoIP Numbers: What's the Difference and Why It Matters for Verification
What non-VoIP numbers are, how apps detect VoIP with line-type lookups, why Google Voice and TextNow get rejected, and when each number type works.
Read the guide →Safety & privacyHow to Stop Spam Texts and Calls (US, UK and Canada)
Cut down spam texts and calls: forward to 7726, use carrier and phone filters, join Do Not Call lists, and keep your number off sign-ups.
Read the guide →Safety & privacyWhy Websites Ask for Your Phone Number, and When It's Worth Giving
Why sites and apps ask for your phone number: bot prevention, 2FA, recovery, marketing and data. When it's worth giving and when to hold back.
Read the guide →Getting startedWhat Is a Virtual Phone Number? VoIP, Rented SMS Numbers and eSIMs Explained
What a virtual phone number is, how VoIP numbers, rented SMS numbers and eSIMs differ, and what kind of numbers Noir SMS provides.
Read the guide →Noir SMS temporary number vs Google VoiceTemporary virtual number vs Google Voice
Google Voice is a free, long-term US VoIP number many apps reject. A Noir SMS temporary mobile number is for one verification. Which fits your sign-up?
See the comparison →Noir SMS temporary number vs TextNowTemporary virtual number vs TextNow
TextNow gives a free ad-supported VoIP number that can be reclaimed if unused. A temporary mobile number handles one code. Compare acceptance and setup.
See the comparison →