How to Stop Spam Calls in Brazil
Brazil has some of the world's highest spam-call rates — banks, loans, telemarketing and scams. If Não Perturbe hasn't stopped them, here's the approach that reliably works on Android.
Step 1: Register on "Não Perturbe" and watch the 0303 prefix
Anatel's Não Perturbe service (naoperturbe.com.br) lets you block telemarketing from participating companies, and Anatel requires telemarketing calls to use the 0303 prefix so they're easy to recognize. Useful — but the worst offenders (scams and non-compliant callers) skip both, so the calls keep coming.
Step 2: Block every number not in your contacts (the reliable fix)
Spam numbers in Brazil are endless and frequently spoofed, so blocking them one at a time can't keep up. Android 10+ has a call-screening role that handles calls from numbers not in your contacts before your phone rings — matching contacts inside Android, so the app never reads your contact list.
- Install the app Get Block Unknown Callers from Google Play — free, no sign-up, no contacts access.
- Set it as your call-screening app Confirm the role in the system dialog.
- Choose Block or Silence for non-contacts — reject them, or mute the ringer while keeping them in your log.
- Add exceptions Use the allow list and repeat-call bypass so your bank, delivery, or a new work number get through. You can also block the 0303 prefix outright.
Why this beats Não Perturbe and blocklists
Não Perturbe only binds participating, compliant companies — not scammers.
Number blocklists can't keep up with spoofed, ever-changing numbers.
"Not in my contacts" stops the whole category before it rings, while people you know come through normally — and you can additionally block the 0303 telemarketing prefix.
Free · No sign-up · No contacts access
More: stop robocalls & scam calls · block international spam · spam call statistics
Frequently asked questions
Why do I still get spam calls after registering on Não Perturbe?
Não Perturbe only binds participating, compliant companies. Scammers and non-compliant callers ignore it, so the worst calls keep coming. Blocking every number not in your contacts stops them regardless.
What is the 0303 prefix in Brazil?
Anatel requires telemarketing calls to start with 0303 so you can recognize them. You can choose to block that whole prefix in a call-screening app.
Do I need to give an app my contacts?
No. Android matches contacts internally, so a call-screening app blocks unknown numbers without requesting contacts permission.
Is the app free?
Yes — free and ad-supported, with no subscription and no sign-up.
Will I miss important calls?
Save important numbers to contacts or add them (or whole prefixes) to the allow list; repeat-call bypass also lets urgent callers through.