Should you reply STOP to a spam text?

Reply STOP only to a business you actually signed up with; to a number you don't recognize, don't reply at all, because any reply confirms your number works. For unknown senders, delete the text and report it to 7726 or through your messaging app instead.

When does replying STOP work?

It works when the sender is one you agreed to hear from. Say you gave your number to a store and now get its sale texts every week. You did sign up, and you want them to stop.

Here, reply STOP. The FCC treats a reply of "stop" as a reasonable way to take back your consent to automated texts you agreed to receive. Once you've taken it back, that sender may not send you more robotexts.

The rule is about consent you gave. That's why it fits the store you signed up with, and not a stranger you never heard from before the first text.

Why is replying STOP to a spam text a bad idea?

Because to an unknown sender, STOP is still a reply. The FTC's advice is plain: don't reply to text messages from unknown numbers. Even a short reply means you've "confirmed they reached a working telephone number," and the FTC warns that this could bring more calls and texts from scammers.

Picture a text that reads "Congratulations, you've been selected for a gift card. Reply YES to claim." Replying YES tells the sender someone is there. So does replying STOP. By the FTC's reasoning, both confirm the same thing: the number works.

How can you tell which kind of sender it is?

Start with a simple question: did you sign up with this business? If you can't remember, treat the text as unexpected.

When a business you don't recall texts you, the FCC's advice is to find the company's number on your own and call it. The FTC puts it this way: reach the company through a phone number or website you've confirmed is real, and ignore the contact details in the text.

What should you do instead of replying?

For a business you signed up with, reply STOP, as above. For a text from a number you don't know:

1. Don't reply, not even STOP. 2. Leave any link in it alone. 3. Report it. Send it on to 7726 (SPAM on a phone keypad), which the FTC says helps your wireless provider find similar messages and block them in future. Or use the junk or spam report in whatever messaging app you use, or file it at ReportFraud.ftc.gov. 4. Delete it.

On Android, marking a conversation as spam in Google Messages blocks the sender too, and the thread goes to Spam & blocked. On an iPhone, Apple says a report won't keep that sender from messaging you, so block the number as well if you want it blocked.

Where does a number lookup fit?

Checking the number that texted you adds context before you decide. A Lookup Pass lookup gives you the carrier, the line type (mobile, landline, or internet), a caller ID name if the number has one, and national scam and spam reports. The name comes from the number's record on file and isn't proof of the sender. If no reports come back, nothing has been filed on this number. A result like that is not the same as safe. If people have reported it, that's one more reason not to reply.