What can a number lookup tell you, and what can't it?

A number lookup shows the carrier behind a number today, its line type, the caller ID name on file, and any reports of scams or spam against it. It can't identify the person using the phone, say where they are, or tell you whether the caller is honest.

What does each part of a lookup mean?

The carrier details are read from the carrier network when you run the check, and the number is then compared with national scam and spam reporting. Here is what comes back and how to read it.

The carrier. This is the company carrying the number's calls and the one carrying its texts, as of today. Numbers can move from one carrier to another, so this is the current carrier, not the one the number was first issued by.

The line type. A lookup reports one of three kinds: mobile, landline, or internet (VoIP). The line type describes the number itself, separate from any name the caller sends.

The caller ID name on file. When a number has one, you see the name on file for it. It is useful context. It is not proof of who is sending the call or text. A name like that is easy to send; the number's carrier is much harder to fake.

Scam and spam reports. These come from national scam and spam reporting. Different reporting sources use different rules; a label is not proof of who called. Read reports as a warning from other people, not as proof of what the caller intends. Reporting a number yourself takes one tap in the app.

What can't a lookup tell you?

• Who is using the number. A lookup describes a number. It won't identify the person behind it, and it doesn't search for people.
• Where anyone is. A lookup never shows a person's location.
• Whether a caller means well. No warning means none was found in the sources checked. That is not the same as safe. Some scam calls are never flagged, as the FTC points out.
• Who really called, if the number was faked. Scammers can fake any name or number on caller ID, the FTC says. Your results are about the number your phone displayed. If that display was spoofed, you are reading about the number shown, not the real caller.
• Whether the call really came from your bank or an agency. Only the organization can confirm that. The FCC's advice is to hang up and phone them back using the number on your account statement or their own website.
• Senders that aren't 10-digit numbers. Lookups cover 10-digit US phone numbers only. Automated business texts from 5- or 6-digit short codes, and messages that show a company name instead of a number, fall outside that.

How does a lookup help with a real call?

Take three common situations.

A missed call from your own area code. The FTC describes neighbor spoofing, where the displayed number matches your area code, and often your number's first six digits. A lookup shows what the carrier network has for that number: what kind of line it is and whether people have reported it. If it comes back as an internet line with scam reports against it, that is a reason to doubt the local look, though it doesn't prove who called.

A call that rang once. Check the area code before anything else. The FCC points out that codes like 649 and 809 look domestic but reach the Turks and Caicos and the Dominican Republic, and that returning such calls can bring connection and per-minute charges. If it is a US number, a lookup then shows whether other people have reported it before you decide whether to return it.

A voicemail asking you to call back. You can look up both the number that called and the number in the message. Whatever comes back, return the call on a number you found yourself, not the one in the voicemail.

Where can you run a lookup?

Lookup Pass checks any US number, in any browser, and you can add it to your home screen. The app is on Google Play; you can share a number into it straight from a text or the call log, and the app never reads your contacts, your call history or your messages.