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

A Lookup Pass lookup shows who carries the number, its line type, any caller ID name on file, and scam or spam reports against it. It can't find who is texting you or say where they are, and a clean result is not the same as safe.

What does a lookup show for a number that keeps texting you?

When the same number keeps texting, or a new one turns up with the same pitch, you can run a lookup on it. Lookup Pass works with any US number. It reads the carrier network live, as you check, and then searches national scam and spam reporting for the number. You get four things back:

• The carrier. Two names, in fact: the company handling the number's calls and the one handling its texts. You see who carries them now, not who carried them first.
• The line type. Mobile, landline, or internet (VoIP): the kind of line behind the number.
• The caller ID name. Shown whenever the number has one.
• Scam and spam reports. What people across the country have reported about it.

Together, these details describe the number. They don't prove who sent the text, and the limits below matter as much as the result.

If the same gift card pitch keeps arriving from different numbers, look up each one as it arrives. Each one gets its own result.

What can't a lookup tell you?

Five things, and it's good to know them before you read a result:

1. Who has the phone, or where they are. A lookup describes the number itself. It won't locate anyone, and it isn't a tool for finding people. 2. Proof of who sent the text. The caller ID name is simply the name on file. It doesn't prove who is sending. What the network reports about the number, its carrier and line type, is much harder to fake than that name. 3. That a number is harmless. No reports means nobody has reported the number so far, and that is not the same as safe. 4. Who is behind a spoofed number. The FTC has warned that the number on a text can be faked, even to show your own. The lookup covers the number on your screen, so with a spoofed number you're reading about that number, not the real sender. 5. Spam from short codes or business names. Lookups work on 10-digit US phone numbers. When spam arrives from a short code (a 5- or 6-digit sender of the sort businesses use for automated texts), or a business name sits where the number should be, there's nothing for a lookup to check.

How do you use a lookup with the other steps?

Treat the lookup as one more thing to know before you act, not the last word.

1. Share or paste the number. You hand the app the number by sharing it from the text. Your call history, contacts, and messages are never read by the app. 2. Read the result. If people have reported the number, don't reply and don't tap any link. Delete it and report it. 3. If nothing has been reported, fall back on what you know. Did you sign up with this sender? If it's a store you really did join, replying STOP is the right move: a sender you signed up with has to stop texting you once you reply STOP. If you never signed up, the FTC's advice holds: don't reply to texts from unknown numbers.

How does a number get labeled for spam?

People report it. A number gets a label that everyone sees only when reports come in from several different people. A single report won't do it, so no one person can label a number alone.

You can add to that. The Lookup Pass app lets you report a number with one tap, and that sits alongside the other reporting routes for spam texts: forwarding to 7726, your messaging app's report option, and ReportFraud.ftc.gov.

Lookup Pass runs in any browser and can sit on your home screen. On Android, get the Lookup Pass app from Google Play.