The primary way to use a phone number is through Facebook's "Find Friends" feature, which syncs with your phone's contacts. This method works if the person you're looking for has allowed their number to be discovered.
On Mobile (Facebook App):
Sync Your Contacts: This is the most crucial step.
Tap the Menu icon (☰) on Android, or the bottom-right Menu icon on iPhone.
Scroll down and tap Settings & Privacy, then Settings.
Scroll down to the Permissions section and tap Upload Contacts.
If it's turned off, toggle it On. This allows Facebook to scan your phone's contact list.
Search in the "Find Friends" Section:
Go back to the Menu.
Tap Find Friends.
Here, you will see a list of "People You May Know." This list is generated from various signals, including your synced contacts. If the person with that phone number is in your contacts and has linked it to their Facebook profile, they should appear here.
On Desktop (Facebook Website):
Go to the Facebook homepage.
Click on the Find Friends link in the left-hand menu.
On the "Find Friends" page, look for a section titled "Contacts." You might be prompted to upload your contacts. If you have already synced them, you can browse the list.
Direct Search in the Search Bar:
You can also try typing the phone number directly into the main Facebook search bar at the top of the screen.
Format: Try entering the number with the country code (e.g., +1 555 123 4567).
Limitation: This will only work if the person has set their privacy setting for "Who can look you up using the phone number you provided?" to "Everyone."
Why It Might Not Work (And What to Do Instead)
This method is not guaranteed. Here are the main reasons why and some alternatives:
Privacy Settings: This is the biggest factor. Users can set their "Who can look you up using your phone number?" privacy setting to "Friends" or "Only Me," which will prevent you from finding them unless you are already friends.
The Number Isn't Linked: The person may not have added that specific phone number to their Facebook account.
You've Already Blocked Each Other: If either of you has blocked the other, the profile will not appear in search results.
What to try instead:
Search by Name: Combine the name with other details you know, like their city, school, or workplace.
Check Mutual Friends: If you have mutual friends, browse their friends list.
Use Other Platforms: Try searching for the number on other social media apps like Instagram (which is owned by Meta/Facebook) or LinkedIn, or use a search engine like Google.
Important Privacy Note
Facebook's ability to match phone numbers to profiles is a powerful feature. To control your own privacy, go to Settings & Privacy > Settings > Privacy > How People Can Find and Contact You and review the "Who can look you up using the phone number you provided?" option. It is recommended to set this to "Friends" for better privacy.
