What blocking a contact actually does
Blocking a contact stops that person from calling, texting, or messaging you through the app or service where you blocked them. On most phones and messaging platforms, a blocked person can still leave a voicemail, but you won't be notified. They won't know they're blocked — the call or message will just fail silently on their end, or they'll see a generic "message not delivered" error.
Blocking is not the same as deleting. The contact stays in your phone or account, but hidden from your normal view. You can unblock them later if you change your mind. Blocking also doesn't prevent someone from contacting you through a different number, email address, or app — it only stops that specific contact on that specific service.
Key Takeaways
- Blocking stops calls, texts, and messages from reaching you, but the blocked person won't receive a notification that they're blocked.
- The steps to block differ by device and app — iPhone, Android, Gmail, Facebook, and WhatsApp each have their own process.
- A blocked contact can still reach you through a different phone number or account, so blocking one contact doesn't prevent all contact from that person.
- You can unblock a contact at any time by finding them in your blocked list and reversing the block.
How to block someone on iPhone
Open the Phone app and find the contact you want to block. Tap the "i" icon next to their name, scroll to the bottom, and tap "Block this Caller." The contact is now blocked — they can't call or text you, though they may see a message saying the call failed.
You can also block a contact from the Messages app. Open a conversation with that person, tap their name at the top, scroll down, and select "Block this Caller." To unblock them later, go to Settings > Phone > Blocked Contacts (or Settings > Messages > Blocked Contacts for text), find their name, and tap "Unblock."
How to block someone on Android
Open the Phone app and find the contact. Press and hold their name, then tap "Block number" or "Block contact" — the exact wording depends on your phone model and Android version. Some Android phones also let you block from the contact details screen by tapping the three-dot menu and selecting "Block."
To block someone in Messages on Android, open the conversation, tap the three-dot menu at the top, and select "Block." To see your blocked list, go to Settings > Apps > Messages > Blocked, or check the Phone app's settings for a "Blocked numbers" section. The location varies by manufacturer.
How to block someone in Gmail and email
Open an email from the person you want to block. Click the three-dot menu icon in the top right, then select "Block [sender]." Gmail will automatically send their future emails to spam. You can also block someone by opening their contact card and clicking the block icon.
To unblock them, go to Settings > Filters and Blocked Addresses, find their email in the blocked list, and click "Unblock." Other email services like Outlook and Yahoo have similar options — usually in Settings or under a "Blocked senders" list. Check your email provider's help section if you can't find the block option.
How to block someone on social media and messaging apps
Facebook: Go to their profile, click the three-dot menu, and select "Block." They won't be able to see your profile, message you, or find you in search.
Instagram: Go to their profile, tap the three-dot menu, and select "Block." They can't see your posts, stories, or follow you.
WhatsApp: Open the chat with that person, tap their name at the top, scroll down, and tap "Block Contact." They won't see when you're online or if you've read their messages.
Messenger: Open the conversation, tap their name at the top, scroll down, and select "Block." They can't message you or see when you're active.
X (formerly Twitter): Go to their profile, tap the three-dot menu, and select "Block @[username]." They can't follow you or see your posts unless they log out.
What happens when you block someone
When you block a contact on a phone call or text, they won't receive a notification saying they're blocked. Their call will go to voicemail or fail with a generic error. Their text may show "message not delivered" or simply not send at all, depending on their phone type and carrier.
On social media and messaging apps, the blocked person can't see your profile, posts, or stories. They can't message you, and if they try to search for you, they won't find your account. However, they may figure out they're blocked by noticing they can't reach you or see your profile anymore.
Blocking does not delete old messages or calls. Those remain in your phone's history unless you manually delete them. If you unblock someone later, the old conversation history will still be there.
When you might want to block someone
Block a contact if they're harassing you, spamming you repeatedly, or if you need a clean break from someone. Blocking is also useful if you're trying to avoid contact during a difficult time and don't want to be tempted to respond.
Blocking is not a substitute for reporting abuse. If someone is threatening you, harassing you, or sending unwanted sexual content, report them to the platform or service and consider contacting local police. Most apps have a "Report" option alongside the block option.
Frequently Asked Questions
Can a blocked person tell they're blocked?
Not officially — they won't get a notification. But they may figure it out if calls go straight to voicemail, texts don't deliver, or they can't find your social media profile. On some platforms like iMessage, repeated failed messages might make it obvious.
Can a blocked person still reach me another way?
Yes. Blocking only stops contact through that specific number, email, or account. They can call from a different number, email from a different address, or message you through a different app. If someone is harassing you across multiple channels, document it and report it to the platform or police.
What if I block someone by mistake?
You can unblock them anytime. On iPhone, go to Settings > Phone or Messages > Blocked Contacts and tap "Unblock." On Android, open the Phone or Messages app settings and find your blocked list. On social media, go to their profile and select "Unblock."
Does blocking delete our chat history?
No. Blocking hides the contact from your normal view, but old messages and calls remain in your phone or app unless you manually delete them. If you unblock them later, the history is still there.
Can I block someone without them knowing?
Yes, blocking is silent — they won't receive a notification. They may eventually notice they can't reach you, but the block itself happens without any alert to them.