The fastest way to block a text sender depends on your phone type

Most phones let you block a number directly from a text thread — open the message, tap the sender's number or name, and choose "Block" or "Block this Caller." On iPhone, this option appears when you swipe left on the message or tap the info icon. On Android, long-press the message thread and select "Block" or look for a block option in the thread details. The blocked number won't be able to text you, call you, or reach you through FaceTime or iMessage, depending on your phone.

If you don't have a previous message from the number you want to block, you can add it to your contacts and mark it as blocked. On iPhone, go to Contacts, create a new contact with that number, then go back to the Contacts app settings and select "Block this Caller." On Android, open Contacts, create a new contact, save it, then open your phone's settings, find Call or Message blocking, and add the number there.

Some carriers also offer blocking through their own apps or online portals. Verizon has Call Filter, AT&T has Call Protect, and T-Mobile has Scam Shield — these apps can block numbers at the network level before texts even reach your phone. Check your carrier's website to see what tools come with your plan.

Key Takeaways

  • You can block a number directly from a text message by swiping or tapping the sender's info and selecting "Block."
  • Blocked numbers cannot text you, call you, or reach you through messaging apps like iMessage or FaceTime.
  • If you don't have a message from the number yet, create a contact for it and mark it as blocked in your phone's settings.
  • Your phone carrier may offer a separate blocking app that stops texts before they reach your device.
  • Blocking is not the same as reporting spam — you may want to report the number to your carrier or to the FTC if it's harassment or fraud.

How blocking works on iPhone

On iPhone, blocking a number prevents that sender from reaching you through text, call, FaceTime, or iMessage. Open the Messages app, find the conversation with the number you want to block, and swipe left on it. A red "Unblock" button will appear — tap it to reveal the block option. Alternatively, tap the info icon (the circle with an "i") at the top right of the conversation, scroll down, and tap "Block this Caller."

Once you block a number on iPhone, any existing messages from that sender stay in your Messages app, but you won't receive new ones. The blocked person won't know they're blocked — their messages will simply fail to send without a delivery notification. If you change your mind, you can unblock the number by going to Settings > Messages > Blocked Contacts (or Settings > Phone > Blocked Contacts for calls) and swiping left on the number to unblock it.

How blocking works on Android

Android blocking varies slightly by manufacturer and version, but the basic process is similar. Open your Messages app (or the default SMS app on your phone), find the conversation with the number you want to block, and long-press it. A menu will appear with options including "Block" or "Block number." Tap it to confirm. Some Android phones also let you tap the sender's number at the top of the conversation and select "Block" from there.

If your Android phone uses a different messaging app — like Google Messages, Samsung Messages, or another third-party app — the steps may differ slightly. Google Messages, for example, lets you swipe left on a conversation and tap the block icon. Check your specific app's menu or settings if the standard method doesn't work. Like iPhone, blocked numbers on Android won't be able to text or call you, and existing messages usually remain visible in your app.

Blocking through your carrier's network

Carrier-level blocking stops texts before they reach your phone, which can be more effective for spam and robocalls. Verizon's Call Filter app blocks known spam numbers automatically and lets you add custom numbers to a block list. AT&T's Call Protect works similarly, filtering spam calls and texts. T-Mobile's Scam Shield offers free and paid tiers, with the paid version blocking more aggressive spam.

These apps work differently from phone-level blocking because they operate at the carrier's network, not just on your device. This means a blocked number may not even attempt to reach you. Some carriers include basic blocking for free with your plan, while others charge a small monthly fee for advanced features. Check your carrier's website or call customer service to see what's included with your account and how to turn it on.

What happens when you block a number

When you block a number on your phone, the blocked sender cannot text you, call you, or reach you through iMessage, FaceTime, WhatsApp, or other apps linked to your phone number. Their messages won't appear in your inbox, and they won't receive a notification that they've been blocked — their text will simply fail to send or appear to send without a delivery confirmation.

Blocking is one-way: you won't see their messages, but they can still see old conversations with you if they saved them. If you block someone and then unblock them later, they will not see a record that you blocked them. Your phone keeps a list of blocked numbers in your settings, so you can review or remove blocks at any time.

Blocking spam and unknown numbers

If you receive spam texts from numbers you don't recognize, you have a few options beyond blocking. Many phones now have a "Filter Unknown Senders" setting that separates texts from people not in your contacts into a separate folder. On iPhone, go to Settings > Messages and toggle on "Filter Unknown Senders." On Android, this option varies by phone, but you can usually find it in your Messages app settings under "Spam protection" or "Advanced."

You can also report spam texts to your carrier and to the Federal Trade Commission. Forward spam texts to 7726 (SPAM) on most carriers, or check your carrier's website for their spam reporting process. Reporting helps carriers identify and block spam sources at the network level, which protects other customers too. If the spam is harassment or fraud, you may want to keep records of the messages before blocking the number.

Unblocking a number if you change your mind

On iPhone, go to Settings > Messages > Blocked Contacts (or Settings > Phone > Blocked Contacts if it's a call blocker) and swipe left on the number you want to unblock. Tap "Unblock." On Android, open your Messages app, tap the menu icon, go to Settings > Blocked numbers, and tap the number you want to unblock, then select "Unblock."

After you unblock a number, that person can text and call you again, and you'll receive their messages normally. They won't know you unblocked them. If you want to block them again later, you can repeat the process. Keep in mind that unblocking doesn't restore old messages from when they were blocked — those are usually deleted from your inbox.

Frequently Asked Questions

Can someone tell if I blocked them?

No. When you block a number, the sender won't receive a notification that they're blocked. Their text may appear to send, or it may fail silently. They won't see a "blocked" message or any other indicator. The only way they'd know is if they tried to reach you through another method and you didn't respond.

Will I still see old messages from a blocked number?

On most phones, yes. Blocking a number stops new messages from coming in, but old conversations usually stay in your Messages app. You can delete the conversation manually if you want to remove it. Some phones and apps handle this differently, so check your specific phone's settings.

What's the difference between blocking and reporting spam?

Blocking stops a number from reaching you personally. Reporting spam tells your carrier or the FTC that the number is sending unwanted messages, which helps them identify and block the source for everyone. You can do both — block the number to stop receiving texts from it, and report it to help stop the spam at the source.

Can I block a number if I don't have their message yet?

Yes. Create a new contact with that number, save it, then go to your phone's settings and add it to your blocked list. On iPhone, you can also add it through Settings > Messages > Blocked Contacts. On Android, go to your phone's settings, find Call or Message blocking, and add the number there.

Do I need to pay for blocking, or is it free?

Phone-level blocking built into your device is free. Carrier-level blocking apps like Verizon Call Filter or AT&T Call Protect may be free or cost a few dollars per month depending on your plan and the features you want. Check your carrier's website to see what's included with your account.