Where to find blocking tools on your phone

Both Android and iPhone have built-in tools to block text messages, and they work differently depending on which phone you use. On an iPhone, you open the Messages app, find the conversation you want to block, swipe left on it, and tap "Block This Caller." On Android, the steps vary by manufacturer — Samsung phones have a "Block" option in the Messages app when you long-press a conversation, while Google Pixel phones let you tap the three dots at the top of a conversation and select "Block."

The advantage of using your phone's native blocking is that it stops texts from that number entirely. The blocked sender won't know they're blocked, and their messages won't appear in your inbox or notification center. If you change your mind, you can unblock the number the same way you blocked it.

Key Takeaways

  • Your phone's built-in messaging app has a block feature that stops texts from a specific number from reaching your inbox.
  • Blocking through your carrier (AT&T, Verizon, T-Mobile, etc.) stops texts before they reach your phone and may cost a small monthly fee.
  • Third-party apps like TrueCaller and RoboKiller can filter spam and unwanted texts, but they require permission to read your messages.
  • Blocking a number does not stop the sender from leaving voicemails, so you may need to block them in your phone's call settings separately.
  • If you receive threats or harassment, report the number to your carrier and local police rather than blocking alone.

Blocking through your wireless carrier

AT&T, Verizon, T-Mobile, and other carriers offer text-blocking services that work at the network level, meaning they stop unwanted messages before they reach your phone. AT&T Call Protect and Verizon Call Filter both have free versions that block known spam, and paid tiers that add more aggressive filtering. T-Mobile includes spam filtering in its network by default for most customers.

Carrier-level blocking is stronger than phone-level blocking because it catches messages from spoofed numbers and bulk senders that your phone might not recognize. The trade-off is that some paid plans cost $3 to $5 per month, and you need to log into your carrier's website or app to manage your blocked list. If you block a number through your carrier, it blocks it for all your devices on that account.

Using third-party apps to filter texts

Apps like TrueCaller, RoboKiller, and Samsung's native spam filter (on newer Galaxy phones) can identify and block spam texts automatically. These apps work by comparing incoming messages against databases of known spam numbers and patterns. Some apps also let you create custom block lists or set rules — for example, blocking all texts from unknown numbers while allowing contacts.

The main thing to understand about third-party apps is that they need permission to read your text messages to work. Before you install one, check what permissions it asks for in your phone's settings. If an app asks for permission to access your contacts, location, or photos when its job is just to filter texts, that is a sign to look for a different option. Reputable apps like TrueCaller are transparent about what data they collect, but smaller or lesser-known apps may not be.

What happens when you block a number

When you block a number on your phone, that person's text messages stop appearing in your Messages app, and you won't get notifications when they text you. However, they can still leave voicemails — blocking texts does not automatically block calls or voicemail. If you want to block both, you need to block the number in your Phone app as well.

The blocked sender has no way to know they are blocked from the phone's perspective. Their message may appear to send normally on their end, or they may get a delivery failure after a delay. This is different from blocking on social media or messaging apps, where the person often sees a message saying they are blocked.

Blocking spam and robocalls disguised as texts

Some unwanted texts come from automated systems that spoof real phone numbers or use short codes (five- or six-digit numbers instead of full phone numbers). These are harder to block individually because the number changes or is not a real phone number. This is where carrier filtering and third-party apps become more useful than blocking a single number.

If you receive a text from a short code, you can reply with the word "STOP" to unsubscribe from that sender. This works for legitimate marketing texts and alerts, though scammers often ignore it. If a text asks you to click a link or reply with personal information, do not respond — that is a common phishing tactic. Instead, report it to your carrier or to the Federal Trade Commission's spam reporting tool.

When to report instead of just blocking

If you receive threatening messages, harassment, or texts that appear to be part of a scam targeting multiple people, blocking alone is not enough. Report the number to your carrier's abuse team — most carriers have a way to report spam or harassment through their website or by forwarding the message to a specific number. You can also report it to the FTC at ReportFraud.ftc.gov or to your local police if the messages contain threats.

Carriers and law enforcement use reports to identify patterns and shut down operations that target many people. If you are being harassed by someone you know, document the messages (take screenshots with the date and time visible) before blocking, because you may need them if the situation escalates.

Frequently Asked Questions

Can someone tell if I blocked their number?

Not directly from your phone. Their text may appear to send normally or fail after a delay, but they won't see a message saying they are blocked. Some people figure it out by noticing a pattern — their messages never get responses — but your phone does not notify them.

Will blocking stop voicemails from that number?

No. Blocking a text message number only blocks texts. If you want to block calls and voicemails too, you need to block the number in your Phone app separately. On iPhone, open the Phone app, find the number in your recents or contacts, and tap "Block This Caller."

What is the difference between blocking and reporting spam?

Blocking stops that specific number from reaching you. Reporting tells your carrier or the FTC that the number is spam or a scam, which helps them investigate and potentially shut it down for everyone. You can do both — report it first, then block it.

Do I need to pay for a carrier blocking service if my phone has a built-in block feature?

Not necessarily. Your phone's built-in blocking works fine for numbers you know. Paid carrier services are worth it if you receive a lot of spam or spoofed numbers, because they filter at the network level before messages reach your phone. Free carrier filtering (like T-Mobile's default spam filter) is a good middle ground.