Spam calls and unwanted texts are a modern nuisance, but your Nothing Phone (3) has the tools to shut them down. Blocking a number is a straightforward process that stops all calls and messages from that contact. I'd start by using the Phone or Messages app, as that's usually the quickest way to get it done.
Block a Number from Your Call Log
Open the Phone app and tap the Recents tab. Find the number you want to block in your call history. Tap on it to view the call details, then look for the block option. On Nothing OS, this is often a button labeled Block/report spam or found under a three-dot menu. Confirm your choice, and that number will be silenced.
Block Someone from a Text Conversation
If the spam is coming via SMS, open the Google Messages app. Find and open the conversation with the unwanted number. Tap the three-dot menu in the top-right corner and select Details. From there, you should see an option to Block & report spam. This blocks future messages and helps improve spam detection for everyone.
Block a Contact Directly
For people already in your address book, open the Contacts app. Select the contact you wish to block to open their details page. Tap the three-dot menu icon, then choose Block or Block numbers. This action will block every phone number associated with that contact, which is useful if someone tries reaching you from multiple lines.
Manage Your Blocked List
To see who you've blocked or to unblock someone, go to your Phone app's settings. Tap the three-dot menu, then go to Settings > Blocked numbers. You'll see a complete list. Tap the X or Unblock button next to any entry to remove the block. You can also add numbers to this list manually if you have a number you want to preemptively block.
Turn on Spam Protection
Your Nothing Phone (3) uses Google's dialer framework, which includes powerful spam filtering. Go to Phone app > Settings > Caller ID & spam. Make sure the options for See caller and spam ID and Filter spam calls are toggled on. With this enabled, calls identified as spam will be flagged in red or sent directly to voicemail without ringing.
Silence Calls from Unknown Numbers
For a more aggressive approach, you can silence all calls from numbers not in your contacts. Within the Phone app settings > Blocked numbers menu, look for a toggle labeled Unknown or Block calls from unknown callers. Turning this on sends all unidentified calls straight to voicemail. Legitimate callers can still leave a message if it's important.
What Actually Happens When You Block
When you block a number, the caller typically hears one ring before being diverted to voicemail, or they may get a message that the line is busy. They aren't notified they've been blocked. Any text messages they send will be silently discarded and won't appear in your Messages app at all. The block is effective and discreet.
Block Unwanted Email Senders
If spam is coming to your Gmail account, you can block it there too. Open the Gmail app, find an email from the sender, and open it. Tap the three-dot menu in the top right. Select Block "[sender]". All future emails from that address will go directly to your Spam folder. For a list of everyone you've blocked, go to Gmail settings and look for the Blocked addresses section.
Consider a Dedicated Call-Blocking App
For the heaviest spam filters, third-party apps like Truecaller can be very effective. These apps maintain massive, crowdsourced databases of spam numbers and telemarketers. After installing one from the Play Store, it will ask for permissions to manage your calls. Once granted, it can identify and block spam automatically before your phone even rings.