How To Block Spam Calls on a Cell Phone
Learn How To Block Spam Calls on a Cell Phone with this helpful tutorial from Zip Tutorials.
Created By: 
Zip Tutorials
Published on March 13, 2025
7 Steps
Step 1:
Enable Built-In Call Blocking
Most smartphones have a basic spam filter—start there. On an iPhone, go to Settings, tap Phone, and turn on Silence Unknown Callers; it sends calls from non-contacts to voicemail. For Android, open the Phone app, tap Settings, then Blocked Numbers or Caller ID & Spam, and toggle on Filter Spam Calls. This quick fix catches a lot of junk right off the bat.
Step 2:
Block Specific Numbers Manually
When a spammer slips through, block them yourself. On iPhone, open the Phone app, hit Recents, tap the “i” next to the number, and scroll to Block This Caller. On Android, go to Call History in the Phone app, tap the number, and select Block or Report Spam. It’s a whack-a-mole game, but it stops repeat offenders cold.
Step 3:
Use Your Carrier’s Spam Tools
Check what your phone provider offers—most have free or cheap call-blocking services. Verizon has Call Filter, AT&T offers Call Protect, and T-Mobile runs Scam Shield; download their app from your app store or call customer service to activate. These use big databases to flag robocalls before they ring, adding an extra shield.
Step 4:
Install a Third-Party App
For tougher spam, grab an app like Hiya, RoboKiller, or Truecaller—find them in the App Store or Google Play. Set one up by granting it phone permissions, then let it screen calls and warn you about telemarketers or scams. Some are free with basic features; others charge a few bucks monthly for premium blocking—pick what fits your budget.
Step 5:
Register with Do Not Call
Head to donotcall.gov and add your number to the National Do Not Call Registry—it’s free and takes a minute. Enter your cell number, confirm via email, and you’re listed. It won’t stop all spam (scammers ignore it), but it cuts legit telemarketing calls within 31 days, slimming down the noise.
Step 6:
Avoid Answering Unknown Calls
Let unfamiliar numbers go to voicemail—if it’s legit, they’ll leave a message. Spammers often hang up, and answering can flag your number as “active” for more calls. Train yourself to ignore the buzz; if it’s important, you’ll hear about it later without feeding the spam machine.
Step 7:
Report Persistent Scammers
If a number keeps bugging you, report it—on iPhone, use that Block This Caller screen to mark it as spam; on Android, tap Report Spam when blocking. You can also tell your carrier or file a complaint at ftc.gov. It won’t zap them instantly, but it helps build data to shut down big offenders over time.
We Think You Might Like These Tutorials
Liked this tutorial? Check out some more tutorials from our community: