How to Block Scam Calls and Filter Spam SMS on Android

Blocking Numbers Directly on Your Phone

The simplest way to stop unwanted calls and texts is to block the numbers directly from your phone's call history or messaging app.

Open your Phone app and go to your Recents or Call History.
Tap on the number you wish to block. On some devices, you may need to tap the 'i' icon for more information.
Look for an option like Block or Block/report spam. Confirm your choice.
To block an SMS sender, open the Messages app, tap on the conversation, then tap the three-dot menu (⋮) and select Block & report spam or Details > Block & report spam.

Tip

Blocking a number prevents them from calling or texting you, but they won't know they've been blocked.

Modern Android phones come with built-in features to identify and block suspected spam calls and messages automatically.

For calls, open the Phone app, tap the three-dot menu (⋮), then go to Settings.
Look for Spam and Call Screen or Caller ID & spam protection.
Ensure that See caller & spam ID and Filter spam calls (or similar) are toggled on.
For Samsung devices (One UI), navigate to Phone > Settings > Caller ID and spam protection and ensure it's enabled.
For messages, open the Messages app, tap your profile icon, then Messages settings > Spam protection. Make sure Enable spam protection is on.

Good to know

These settings use Google's vast database of known spam numbers to help filter out unwanted communications.

Your phone can automatically silence calls from numbers not in your contacts, sending them directly to voicemail.

Open your Phone app, tap the three-dot menu (⋮), then navigate to Settings.
Look for Blocked numbers, then find the option for Silence unknown callers or Block calls from unidentified numbers.
Toggle this feature on.
For Samsung (One UI), go to Phone > Settings > Blocked numbers > Block unknown/private numbers.
Be aware that this might send legitimate calls from businesses or new contacts to voicemail.

Important

While effective, this feature may send important calls from numbers not in your contacts straight to voicemail.

Reporting spam calls and messages to your mobile network provider can help them identify and block these numbers across their network.

For spam texts, forward the message to 7726 (SPAM on your keypad). This works for most UK carriers and is free of charge.
For scam calls, note the number, date, and time of the call.
Contact your mobile network provider's customer service via their website or helpline.
Provide them with the details of the scam call or message.
Consider also reporting persistent scam calls to Ofcom, the UK's communications regulator, on their website.

Tip

Reporting can help protect others from similar scam attempts and strengthens the fight against nuisance communications.

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Written by

Founder, CyberSecurityGuides

Founder of CyberSecurityGuides, writing practical, jargon-free guides that help everyday people recover from and protect against online attacks.

Reviewed by CSG Security Engineers