How to Block Unwanted Calls and Messages

Updated 6 November 2026 · Standard formula, shown below

To block unwanted calls and messages, use your phone’s built-in blocking features, carrier-level blocking services, or third-party apps, depending on your device and the type of nuisance. Start with the native options on your smartphone—they are free, private, and cover most spam and scam numbers.

Why You Receive Unwanted Calls and Messages

Unwanted calls and texts come from several sources. Robocalls use automated dialers to reach thousands of numbers per minute. Scammers often spoof caller ID, making a call appear to come from a local number or a legitimate business. Telemarketers may have obtained your number from public directories or data brokers. Text message spam (sometimes called “smishing”) often contains phishing links or attempts to trick you into revealing personal information. Understanding the source helps you choose the most effective blocking strategy.

Built-In Blocking on iPhone and Android

Both major mobile operating systems include basic blocking tools that work without any additional app.

iPhone (iOS): Open the Phone app, tap the “i” next to the number, scroll down, and tap “Block this Caller.” For messages, open the conversation, tap the contact name at the top, then tap “Info” and “Block this Caller.” You can also block from Settings > Phone > Blocked Contacts.
Android (stock and most skins): Open the Phone app, tap the number, then tap “Block / Report spam.” In Messages, open the conversation, tap the three-dot menu, and choose “Block number.” On Samsung devices, the path is similar: Phone app > recent call > “i” icon > Block.

Blocked callers go straight to voicemail (or are dropped entirely, depending on carrier), and blocked messages are moved to a spam or blocked folder—they don’t notify you. This method is permanent for that specific number, but spammers often call from new numbers, so it’s not a complete solution.

Silence Unknown Callers and Filtering Features

Modern phones include proactive filters that go beyond per-number blocking.

iOS “Silence Unknown Callers”: Settings > Phone > Silence Unknown Callers. This sends calls from numbers not in your Contacts, recent outgoing calls, or Siri suggestions to voicemail. It does not block them—they still ring once and appear in your recent calls list.
Android “Caller ID & Spam Protection”: Available in the Google Phone app (default on Pixel and many others). It identifies suspected spam callers and can automatically screen or block them. Enable it in Phone app > Settings > Caller ID & spam.
Android “Spam Protection” for messages: In the Messages app, go to Settings > Spam Protection and enable it. Messages suspected of being spam are moved to a “Spam & blocked” folder.

These features are free, use on-device or server-side analysis, and require no manual list management. They are often more effective than blocking individual numbers because they adapt to new spam patterns.

Carrier-Level Blocking Services

Major US carriers offer their own call-blocking tools, usually at no extra charge:

AT&T: “Call Protect” (free) blocks likely spam and offers a “spam risk” label. A paid version adds reverse number lookup and custom blocking.
Verizon: “Call Filter” (free) provides spam detection and blocking. The paid tier adds features like number lookup and spam risk meter.
T-Mobile: “Scam Shield” (free) blocks scam calls and labels others. It also includes a “Scam ID” feature that warns you before you answer.

Carrier services work at the network level, so they catch calls before they reach your phone, even when you’re not using data. They don’t block texts, however, and their effectiveness varies by region and scam type. You usually activate them through the carrier’s app or website.

Third-Party Call and Text Blocking Apps

If built-in and carrier options aren’t enough, dedicated apps offer more aggressive filtering, community-based spam lists, and custom rules. Popular choices include Hiya, RoboKiller, Truecaller, and Nomorobo (the last one is mainly for landlines). These apps:

Use large databases of known spam numbers reported by users.
Allow you to create blocklists based on area code, prefix, or number type.
Offer reverse number lookup to identify unknown callers.
Some (like RoboKiller) use “honeypot” numbers to trap spammers and answer with pre-recorded messages, wasting their time.

Most are free with ads or offer premium subscriptions. They require access to your call logs and contacts, so privacy-conscious users should review permissions carefully. On iPhones, these apps integrate via CallKit and can block calls and identify spam, but they cannot block SMS natively—for that, you need a separate SMS blocker or rely on iOS’s filtering.

How to Block Unwanted Text Messages Specifically

Text spam is handled differently from calls. On both platforms, you can block a specific number, but to filter unknown senders:

iPhone: Settings > Messages > Unknown & Spam. You can enable “Filter Unknown Senders,” which separates messages from people not in your contacts into a separate list. You can also install a third-party SMS filter app (like SMS Filters by Hiya) that works with iOS to automatically sort spam.
Android: The Google Messages app has built-in spam protection that automatically detects and filters suspicious texts. On Samsung, open Messages > Settings > Block numbers and spam > Spam protection. You can also manually add numbers to a blocklist.

For SMS, the most effective approach is a combination of the built-in filter and reporting spam to your carrier (forward the message to 7726, which is “SPAM” on most US carriers). This helps carriers improve their own filters.

Common Problems and Misconceptions

One frequent misconception is that blocking a number prevents the caller from leaving voicemails. On most phones, blocked callers can still leave a voicemail, but it’s stored in a separate “Blocked Messages” folder and you don’t get a notification. Another issue: spammers use “neighbor spoofing”—they display a number that matches your area code and prefix, making it look local. Blocking that specific number won’t stop the next spoofed number. Also, some legitimate calls (like from a doctor’s office or a delivery service) may be flagged as spam by aggressive filters, so check your voicemail and spam folder regularly. Finally, blocking a number on your phone does not prevent the caller from sending you messages through other apps like WhatsApp or iMessage—you need to block them in each app separately.

Frequently Asked Questions

Will blocking a number stop all calls from that number?

Yes, on both iPhone and Android, blocking a specific number will prevent calls and texts from that number from reaching you. The caller may hear a busy tone or a message that your number is not in service, but they won’t be able to get through. However, if the spammer uses a different number, you’ll need to block that one too.

Can I block unknown numbers that don’t show a caller ID?

Yes. On iPhone, “Silence Unknown Callers” sends calls from numbers not in your contacts to voicemail. On Android, you can enable “Block unknown/private numbers” in the Phone app settings. This won’t block calls from numbers in your contacts, so it’s safe to use.

Why do I still get spam texts after blocking the number?

Spammers often use a new number for each campaign, so blocking one number doesn’t stop future texts. Enable your phone’s spam filter (like Google Messages’ Spam Protection or iOS’s Filter Unknown Senders) to automatically catch and isolate these messages. Also, report spam texts to your carrier by forwarding them to 7726.

Are third-party call blocking apps safe to use?

Most reputable apps are safe, but they require access to your call logs and contacts to function. Read the privacy policy and check the permissions you grant. Stick to well-known apps with good reviews. Avoid apps that ask for unnecessary permissions or that display excessive ads.

Does blocking a number on my phone also block it on WhatsApp or other messaging apps?

No. Blocking a number in your phone’s call or message app only affects calls and texts through your carrier. To block someone on WhatsApp, open the chat, tap the contact name, scroll down, and tap “Block.” Similarly, block them in Facebook Messenger, Instagram, and other apps separately.

Can I stop political or fundraising calls?

Political and charity calls are exempt from many do-not-call regulations, so they can still reach you even if you’re on the National Do Not Call Registry. Your best option is to block the specific number or use a call-blocking app that lets you filter by category. Some apps allow you to block “political” or “charity” calls, but they may not catch all of them.

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