Stop Unwanted Text Messages: Blocking and Filtering Guide

Understanding Text Message Spam and Unwanted Messages

Text message spam has grown into a major problem for phone users. According to recent data, Americans receive billions of unwanted text messages each year. These messages range from marketing promotions to scams targeting personal information. Unlike email spam, text messages feel more intrusive because they arrive on devices we carry constantly and often charge us for each message received, depending on our phone plans.

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Unwanted texts come from various sources. Some come from legitimate businesses that have your number through past purchases or sign-ups. Others originate from scammers trying to steal financial information or access to your accounts. A common type is the "smishing" attack, where criminals send messages that appear to be from banks or delivery companies, asking you to click links or provide personal details.

The volume of spam texts has increased significantly over the past five years. Technology has made it easier for senders to obtain phone numbers in bulk, and the relatively low cost of sending SMS messages means spammers can send millions of messages and still turn a profit from a small response rate. Additionally, the rise of spoofed numbers—where senders mask their actual phone number to appear as a local number or trusted business—makes it harder to identify and avoid unwanted messages.

Understanding where these messages come from helps explain why simply replying or clicking "unsubscribe" in a text message can sometimes make the problem worse. When you respond to a spam message, you confirm to the sender that your number is active and monitored, potentially adding your contact information to lists that get sold to other spammers. This knowledge is the foundation for using blocking and filtering strategies effectively.

Practical Takeaway: Recognize that unwanted texts come from multiple sources—some legitimate but unsolicited, others malicious. Avoid engaging with suspicious messages by responding, clicking links, or providing information, as these actions can increase the volume of spam you receive.

Built-In Phone Features for Blocking and Filtering

Both iPhone and Android phones include native tools for managing unwanted text messages without installing additional apps. These built-in features are free and can filter or block many types of unwanted messages automatically. On iPhones running iOS 13 and later, the Messages app includes a feature called "Filter Unknown Senders." This tool separates messages from contacts not in your phone's address book into a separate tab, keeping your main message thread clean from potential spam.

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To enable this feature on iPhone, open Settings, tap Messages, and toggle on "Filter Unknown Senders." Any text from numbers you don't recognize will appear in a separate folder. This doesn't delete the messages—it simply organizes them out of your main view. You can still see these messages if needed by checking the "Unknown Senders" tab. For blocking specific numbers, you can open a message thread from an unwanted sender, tap "Details," and select "Block this Caller." Blocked numbers cannot reach you through Messages, calls, or FaceTime.

Android devices offer comparable features, though the exact location varies by manufacturer and Android version. In most Android phones, you can open the Messages app, long-press a text conversation, and select "Block." Google's Messages app (the default on many Android phones) includes spam filtering that automatically detects and separates suspected spam texts. You can also access this by going to Messages Settings > Advanced > Spam and abuse. For additional control, many Android phones include a "Blacklist" or "Block" feature in their native phone settings under Call and Message Blocking.

These built-in tools work continuously without requiring action from you. They use algorithmic detection to identify common spam patterns and sender characteristics. However, they're not perfect—some spam still gets through, and some legitimate messages might occasionally be filtered. Regularly checking your filtered messages folder ensures you don't miss important communications from actual businesses you work with.

Practical Takeaway: Enable your phone's native filtering features in your Messages app settings. This is often the easiest first step and requires no additional downloads or setup beyond toggling a setting on.

Third-Party Apps and Services for Enhanced Filtering

Beyond built-in phone features, several dedicated apps provide enhanced spam detection and blocking capabilities. Apps like TrueCaller, RoboKiller, and Nomorobo use databases of known spam numbers and employ machine learning to identify new spam patterns. These services maintain crowdsourced lists of reported spam numbers, meaning millions of users contribute data about unwanted texts they receive, which helps identify new spam sources faster than phone manufacturers can alone.

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TrueCaller is one of the most widely used options, available on both iPhone and Android. The app shows caller identity information for incoming calls and texts, and it automatically blocks known spam numbers. It also allows you to create custom block lists and set rules for specific numbers or keywords. The free version blocks spam automatically, while paid versions offer additional features like recording calls or accessing detailed call history.

RoboKiller uses audio fingerprinting technology to identify robocalls and spam texts. Instead of just blocking these messages, it can send automated responses to spam callers, potentially removing your number from active spam lists. The app learns your preferences over time and improves its filtering accuracy. Nomorobo works similarly and is available as both an app and a service that works with some phone carriers.

When selecting a third-party app, consider what data it collects. Many of these services use your contact information to improve their spam detection algorithms. Read the privacy policy to understand what information the app accesses and how it's used. Some people prefer to stick with built-in phone features precisely to minimize data sharing, while others find the trade-off worthwhile for enhanced protection.

Another option is your mobile carrier's spam filtering service. Major carriers like Verizon, AT&T, T-Mobile, and others offer their own spam-blocking tools, sometimes included in your plan or available for a small monthly fee. These services have direct access to network data and can identify and block spam at the network level before messages reach your phone. Calling your carrier's customer service can inform you about what spam management tools are already included in your plan.

Practical Takeaway: Research which third-party app or carrier service aligns with your comfort level regarding data sharing and features you value. Many options exist, and trying different services can help you find what works best for your situation.

Managing and Creating Block Lists

Creating a personal block list involves identifying specific numbers or types of messages you want to prevent from reaching you. This approach works well when you have a small number of known unwanted senders. On iPhone, blocking a contact prevents them from reaching you through Messages, calls, and FaceTime. To block a contact, open the message thread, tap "Details" at the top right, scroll down, and select "Block this Caller." To view or modify your blocked list, go to Settings > Messages > Blocked or Settings > Phone > Blocked Contacts.

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Android users can access their blocked numbers list by opening the Phone app, going to Settings, and selecting "Blocked numbers" or "Block contacts," depending on their phone model. You can block specific numbers directly from message threads, call logs, or by manually entering numbers in your blocked list. Some Android devices allow you to block messages containing certain keywords, which can help with messages promoting products you're not interested in.

When building a block list, keep a few principles in mind. First, don't block numbers based solely on assumptions—verify that a number is actually unwanted before blocking it. Occasionally, legitimate businesses use unfamiliar numbers for text messages. Second, be aware that spammers often use spoofed numbers, so blocking one number won't stop all similar spam. Blocking one "bank scam" text from what appears to be your bank's number won't prevent scammers from sending similar messages using different spoofed numbers.

If you receive messages from a number you don't recognize, you have options beyond blocking. You can ignore the message entirely without responding. If the message appears to be from a business you use, you can contact that business directly using a phone number or website you know is legitimate to verify whether they actually sent the message. You can also report the message to your phone carrier or to the Federal Trade Commission (FTC) if you believe it's a scam.

For frequently changing spam numbers, building a personal block list becomes tedious. This is why combining personal blocking with app-based filtering is often most effective. Use your built-in tools or third-party apps to catch the majority of spam automatically, and maintain a personal block list only for specific recurring nuisances.

Practical Takeaway: Create