How to Block Unknown Callers on Android: Complete Guide for 2026

If spam calls are interrupting your day, you’re not alone—Americans received an average of 2.56 billion robocalls per month in 2025, with most people experiencing 3-4 spam calls weekly. The good news: Android has built-in tools to stop these calls before they even ring.

What is Call Blocking?

Call blocking is a security feature built into Android that prevents calls from specific numbers, unknown callers, or suspected spam sources from reaching your phone. Unlike simply ignoring a call, blocking stops the ringing entirely and sends calls directly to voicemail, giving you complete control over who can contact you.

Android offers multiple blocking methods depending on your needs: intelligent spam filters that learn what’s spam automatically, manual blocking for specific numbers you recognise, and contact-based blocking for people you want to avoid. The exact feature names vary by device manufacturer—Google Pixel uses ‘See Caller & Spam ID’ and ‘Filter Spam Calls,’ while Samsung Galaxy devices use ‘Smart Call’ and ‘Call Assist’ in One UI 8.5 and later.

Current as of: Android 6.0-15.0, February 2026

Why Use Call Blocking?

• Reclaim your peace: Stop the constant interruptions from spam calls, scammers, and unwanted contacts. Your phone becomes yours again.
• Protect yourself from scams: Many spam calls are designed to steal your money, personal data, or identity. Blocking removes this risk entirely.
• Works automatically: Modern spam filters learn from your behaviour and block suspected spam without requiring you to do anything.
• Stay reachable for what matters: Legitimate calls from your doctor, bank, pharmacy, and family get through while spam is silently filtered to voicemail.

Things to Consider Before You Start

• Some legitimate calls might be filtered: Occasionally, real businesses call from numbers not in your contacts. It’s worth checking your blocked list monthly and unblocking if necessary.
• Feature availability varies by device: Older Android phones (Android 9 and earlier) have basic blocking but lack advanced spam filtering. If you have an older device, third-party apps like Truecaller or Mr. Number offer more comprehensive protection.
• Logging behaviour differs by Android version: Android 10 doesn’t log rejected calls in your call history, while Android 11 and later do. This means you may not see a record of blocked calls on older versions.

How to Block Unknown Callers—Three Methods

Method 1: Use Google’s Built-In Spam Protection (Easiest)

This is the simplest way to block spam automatically. Google’s spam filtering works on Android 6.0 and later.

1. Open the Phone app on your Android device (the app with a phone icon).

2. Tap the three horizontal lines (menu icon) in the top-left corner.

3. Select Settings or look for Spam and call screen (exact wording depends on your Android version and device maker).

4. Toggle on the option for ‘See Caller & Spam ID’ or ‘Filter spam calls’ (Google Pixel) / ‘Smart Call’ (Samsung Galaxy) / equivalent on your device.

5. Return to the Phone app’s main screen and look for a filter icon or notification near the top—this confirms spam filtering is now active.

6. Your first filtered call will show ‘Spam likely’ in your call log. You can open the call log to verify the feature is working.

Why this works best: It requires no effort once activated. Google’s AI learns from millions of calls globally and updates in real-time.

Method 2: Block Specific Numbers Manually (For Persistent Callers)

If a particular number keeps calling and you recognise it as spam, block it directly.

1. Let the unwanted call ring or hang up when it arrives.

2. Open the Phone app and tap Recent Calls (usually at the bottom of the screen).

3. Find the number you want to block in your call list.

4. Long-press (press and hold for 2+ seconds) on that number until a menu appears.

5. Tap ‘Block number’ or ‘Block and report as spam’ depending on your device.

6. Confirm your choice when prompted. That number is now blocked.

Check your blocked list regularly: Open the Phone app, go to Settings > Blocked numbers (or Block list). Review this list monthly—if you see a legitimate business blocked by accident (your doctor’s office, pharmacy, or bank), tap it and select ‘Unblock’ to restore their ability to reach you.

Method 3: Block Contacts Through Your Contacts App

If someone has saved a contact on your phone and you want to block them entirely, this method prevents them from reaching you.

1. Open your Contacts app (usually has a person icon).

2. Find the contact you want to block and tap their name to open their contact card.

3. Tap the three dots (more options) in the top-right corner of their contact card.

4. Select ‘Block’ or ‘Block contact’ from the menu.

5. Confirm when prompted. This contact can no longer reach you by phone or message.

Important tip: Add important numbers to your Contacts to prevent them being filtered. Save your doctor’s office, pharmacy, car service, and bank with their business name. These contacts will always ring through, even if they call from an unusual number.

Troubleshooting: When Blocking Doesn’t Work as Expected

Missing important calls? Legitimate numbers might have been filtered by your spam protection. Check your blocked list through Phone app > Settings > Blocked numbers. If you find a business you use, unblock it immediately. Going forward, save these business numbers in your Contacts to prevent future filtering.

Using an older Android phone (Android 9 or earlier)? Older phones have basic blocking features but lack advanced spam filtering. Consider using third-party apps like Truecaller (version 26.6.8 or later, supports Android 8.0+) or Mr. Number (by Hiya) for more comprehensive spam protection. These apps provide AI-powered detection and customizable filtering.

Calls still getting through after blocking? Ensure your Phone app is updated via Google Play Store (latest version 210.0+ as of February 2026). Outdated apps sometimes have bugs. After updating, restart your device to apply changes fully. If international numbers keep calling, check your Phone app settings for regional spam filtering options—you may need to enable additional filters for your country.

Regional note: If you’re in Europe (UK, Germany, France) or Asia, spam call volumes are rising. Whitelisting all important business numbers in your Contacts is especially important for your region.

Blocking unknown callers on Android transforms your phone from a source of constant interruption into a tool under your control. Whether you use Google’s automatic spam filter, manually block specific numbers, or whitelist important contacts, you now have the power to decide who reaches you. Start with Method 1 (automatic spam filtering) today—it requires just 30 seconds to enable and will eliminate the majority of spam calls immediately.