# 'This number is already registered'

A number that someone used before you on the same app may still be attached to their account. The app will not let it verify yours.

## Why does the app say my temporary number is already in use?

Because the number had an account on that app before. SMS Nitro blocks repeat sales of the same number for the same app for a cooling period, but some apps keep the link for months. Cancel the number (no charge) and take a new one; for accounts you plan to keep, rent the number so nobody can take it after you.

## Why numbers get reused

Carrier numbers are reused. A number that finished its reservation is released and may be sold again later for a different app. Marketplaces, including this one, track per-app usage to avoid reselling a number for the same app too soon; apps keep their own records.

## How to avoid it

- Set two-step verification or a recovery email on the account right after sign-up.
- Rent the number for accounts you will log into again (WhatsApp, Telegram, banking).
- Prefer physical-SIM pools for apps that keep long number histories.

## FAQ

**Can someone take over my account later?** Only if the app lets a new owner of the number reset the account and you added no second factor. Add a PIN, password or recovery email.

Source: https://smsnitro.com/help/number-already-registered