If your phone rings with an unknown number and it turns out to be a robocall or a sales pitch, you’re in good company. The fix has two parts: the spam filters built into Android and iPhone, which handle the scammers, and the National Do Not Call Registry, which handles legitimate telemarketers. Use both.
Two kinds of unwanted calls
The right tool depends on who’s calling:
- Telemarketers: real companies selling something. The Do Not Call Registry is meant for them.
- Scammers and illegal robocalls: these ignore the registry, so your phone’s spam filter and your carrier’s tools are your main defense.
How to block spam calls on Android
The Google Phone app comes on Pixel phones and many other Android devices. Its spam filter is a setting you have to switch on yourself.
- Open the Phone app.
- Tap the three dots in the corner.
- Go to Settings > Caller ID & spam.
- Turn on See caller and spam ID.
- Turn on Filter spam calls.
The filter depends on caller ID, so the second setting won’t work unless the first is on. According to Phandroid, with both enabled you should see a significant reduction in spam, though that’s not a guarantee.
Block one specific number on Android
If a number keeps slipping through, open the recent calls list in the Phone app, tap the number and look for the option to block it or report it as spam. Phones from other makers may use a different dialer, so the menus can vary.
Google’s spam setting doesn’t cover text messages. Spam filtering for texts is a separate setting in the Messages app.
How to block spam calls on iPhone
Silence Unknown Callers
- Open Settings.
- Tap Phone.
- Scroll to Silence Unknown Callers and turn it on.
Calls from numbers that aren’t in your contacts go straight to voicemail without ringing, and they still show up in your recent calls. The catch is that you can miss a call you actually wanted from a new number, like a delivery driver or a doctor’s office, so check your recents and voicemail.
Block a specific number
- In the Phone app, open Recents.
- Tap the i icon next to the number.
- Scroll down and tap Block this Caller, then confirm.
Per WebNots, this blocks both calls and texts from that number. To review or undo it, go to Settings > Phone > Blocked Contacts and swipe left on a number to unblock it.
Third-party call-blocking apps
Under Settings > Phone > Call Blocking & Identification, the iPhone lists any call-identification apps you’ve installed. That screen is for turning an app on, not for blocking one number. Read an app’s privacy policy before installing it, since some ask for access to call data.
Register with the National Do Not Call Registry
The registry is run by the Federal Trade Commission and is free. You can sign up two ways:
- Online at donotcall.gov. You’ll need to confirm through an email link within 72 hours.
- By phone at 1-888-382-1222, calling from the number you want to register.
Only register personal numbers, cell phones included. Business and fax numbers aren’t covered, and the FTC warns that anyone who charges you to sign up is almost certainly a scam.
Your number shows up on the registry by the next day, but telemarketers have up to 31 days to stop calling. The registry doesn’t cover political organizations, charities, pure surveys, companies you’ve done business with recently, or companies you’ve given written permission to call.
The FTC page we reviewed is an archived copy, so confirm current details at donotcall.gov.
What to do when a suspicious call comes in
- Don’t share codes, passwords or card numbers over the phone, even if the caller claims to be your bank.
- Hang up and call back using the number on your card or the company’s official website.
- You can report unwanted calls at donotcall.gov, but you need to have been registered for at least 31 days. Complaints about prerecorded robocalls can be filed whether or not you’re registered.
- If scammers reach you on messaging apps too, turn on WhatsApp two-step verification and learn how to tell if someone blocked you on WhatsApp.
Frequently asked questions
Will Google’s spam filter block calls I want?
Occasionally. The feature is off by default partly because legitimate business calls can get filtered, so it’s worth glancing at filtered calls now and then.
If I block a number, can the caller reach me from another one?
Yes. Blocking works on one number at a time, and scammers rotate numbers. That’s why an automatic filter does more than blocking calls by hand.
Does the Do Not Call Registry stop scam calls?
No. It covers telemarketing from companies that follow the rules. Scammers ignore it, so keep your phone’s spam filter on.
How long until the calls stop?
Telemarketers have up to 31 days after you register. Until then, some may still call.
