How to Stop Robocalls & Scam Calls on Android
Robocalls and scam calls keep coming from numbers you've never seen — because that's exactly how they're designed. The most reliable fix is to stop treating every new number as innocent until proven guilty.
Blocklists are always one step behind: you can only block a robocall after it reaches you, and the next one comes from a fresh, often spoofed number. This guide covers what actually works on Android — flipping the logic so that only people you know ring through, plus the extra habits that cut scams.
Why robocalls and scam calls never stop
Most spam and scam calls use number spoofing — the caller ID is faked, often to look like a local number or a real company. Because the source number changes constantly, blocking them one by one is hopeless. Scam operations also dial in huge volumes, so even a tiny response rate is profitable for them. The only durable defense is a rule that doesn't depend on recognizing each bad number.
The most effective fix: block calls not in your contacts
Android 10 and newer include a call-screening role. An app with that role can decide what happens to an incoming call before your phone rings — but only for numbers that aren't already saved in your contacts. That single rule — "if I don't know you, you don't ring" — wipes out the entire category of spoofed, unknown spam at once.
- Install a call-screening app Get Block Unknown Callers from Google Play. It's free, with no sign-up and no contacts access.
- Set it as your call-screening app Confirm the role in the system dialog. That's the only permission it needs.
- Choose Block or Silence Block rejects unknown calls outright; Silence mutes the ringer but keeps them in your log to review later.
- Add exceptions Use the allow list and repeat-call bypass so a clinic, delivery driver, or new work number can still get through.
For the full walkthrough, see our guide to blocking unknown callers.
Extra habits that cut scam calls
Don't engage
Don't press buttons ("press 1 to be removed"), don't answer questions, and don't call back unknown numbers. Any interaction confirms your number is live and invites more calls.
Let unknown calls go to screening or voicemail
Real callers leave a message or are already in your contacts. Scammers usually don't. Blocking or silencing non-contacts handles this automatically.
Use your carrier's spam labeling and STIR/SHAKEN
Many carriers now flag "Scam Likely" calls and verify caller ID with STIR/SHAKEN. It helps, but it only labels calls — it doesn't stop unknown numbers from ringing the way a screening rule does.
Register and report
Where available, add your number to your country's Do Not Call list and report scam numbers to your carrier or regulator. This won't stop spoofed calls instantly, but it feeds the systems that fight them.
Why "not in my contacts" beats a blocklist
A blocklist reacts to numbers you've already seen. Spoofing means you almost never see the same number twice, so the list never catches up. Filtering by the rule "not saved in my contacts" stops the whole category in one move — including numbers that have never called you before — while everyone you actually know rings through normally.
Will I miss important calls?
That's the main worry, so there are several safety nets:
- Contacts always ring — saving a number guarantees it gets through.
- Allow list — permit specific numbers or whole prefixes.
- Repeat-call bypass — an urgent caller who tries again within a short window is let through automatically.
- Silence instead of Block — keep unknown calls in your log to review, without the ringer.
- Pause anytime — turn filtering off when you're expecting an important unknown call.
Free · No sign-up · No contacts access
Frequently asked questions
How do I stop robocalls on Android for free?
Install a call-screening app such as Block Unknown Callers, set it as your default call-screening app, and block or silence every number that isn't in your contacts. It's free and ad-supported, with no subscription.
Why do I still get spam calls after blocking numbers?
Spam and scam calls use spoofed caller IDs, so each call comes from a different number. Blocking individual numbers can't keep up — blocking everything not in your contacts can.
Does stopping robocalls require access to my contacts?
No. Android matches your contacts inside the operating system, so a screening app can filter unknown numbers without ever requesting contacts permission.
Is it safe to answer and press a number to opt out?
No. Pressing a key or speaking confirms your number is active and usually leads to more calls. Let unknown calls be screened instead.
Will my carrier's "Scam Likely" labels stop the calls?
They warn you, but the call still rings. A screening rule that blocks non-contacts stops them before your phone rings at all.