Number recycling
Definition
When a phone number that someone stopped using is reassigned to a new subscriber or user.
Number recycling, explained
Phone numbers are a limited resource, so carriers and VoIP providers reassign numbers that were disconnected or abandoned. After a waiting period, a new person gets the old number and may receive texts meant for the previous owner, including login codes. This is why you should update the number on your accounts before giving one up. Free VoIP numbers can be reclaimed after inactivity, and temporary verification numbers are recycled by design. Noir SMS numbers are single-use and recycled by the provider later, so they should never be the only recovery method on an account you keep.
Related terms
Temporary phone number
A number you use for a short time, often one verification, before it is returned to the provider and reassigned.
Disposable number
A phone number meant to be used briefly and thrown away, so your personal number stays private.
Carrier
A mobile network operator or provider that issues phone numbers and delivers calls and texts.
Where you'll meet this term
SMS Code vs Phone Call Verification: What's the Difference?
When to choose a text code or a phone call for verification, why apps offer "Call me", and what to do if your number can only receive SMS.
Read the guide →TroubleshootingWhy an App Says “This Phone Number Is Already in Use”
Why an app says your phone number is already registered, linked to another account or can't be used, and the legitimate ways to fix it.
Read the guide →Safety & privacyGoogle 2-Step Verification: how to set it up safely
How to turn on Google 2-Step Verification, which second step is safest (passkeys, prompts, authenticator, SMS) and how to avoid getting locked out.
Read the guide →