Spam calls can be a real nuisance, but your Galaxy S25 Ultra has several built-in tools to shut them down. Between Samsung's own Smart Call features and Android's spam protection, you can create a pretty effective barrier against unwanted interruptions.
I'd start with the quickest method if you just got a call from a number you never want to hear from again. Open your Phone app and go to the Recents tab. Find the number, tap on it to see more details, and then tap the three-dot menu in the top right. You'll see an option for Block number. Tap it, confirm, and that number is done.
Block Numbers from Messages and Contacts
If the spam is coming via text, open the Samsung Messages app. Find the conversation, tap the three-dot menu at the top, and select Block number. It's a one-tap process that stops future texts immediately.
You can also block someone directly from your contact list. Open the Contacts app, select the person, and tap the three-dot menu on their details page. Choose Block contact to block all phone numbers and email addresses associated with that contact.
Manage Your Entire Blocked List
To see everyone you've blocked or to manually add a number, go to your Phone app's settings. Tap the three-line menu, then go to Settings > Block numbers. You'll see the full list here.
You can remove a number from the block list by tapping the minus icon next to it. This is also where you can type in a number to block it preemptively, which is handy if you're getting repeated calls from a certain pattern.
Turn On Automatic Spam Protection
Your S25 Ultra's most powerful feature is its automatic filtering. Go to Phone app > Settings > Caller ID and spam protection. Make sure the main toggle is on.
With this enabled, Samsung's Smart Call service uses Hiya's database to identify and warn you about suspected spam calls right on your incoming call screen. For even more peace of mind, tap Block spam and scam calls on that same settings page to have the phone automatically reject them.
Silence Calls from Unknown Numbers
If you only want calls from people in your contacts, there's a setting for that. Within the Block numbers menu in your Phone settings, look for the toggle labeled Block calls from unknown numbers.
Turn this on, and any call from a number not saved in your contacts will be silenced. They can still leave a voicemail, so you won't miss anything important from a doctor's office or delivery person. It's a great way to eliminate random calls during your day.
What Actually Happens When You Block
When you block a number on your Galaxy, what the caller experiences depends on your carrier. Usually, they'll hear a few rings and then be sent to voicemail, or they might get a busy signal. They won't receive any notification that they've been specifically blocked.
On your end, calls and texts from that number simply disappear. You typically won't see a missed call notification or a new message thread. Everything is silently filtered out before it reaches you.
Report Spam to Help Everyone
You can contribute to fighting spam at the network level. If you get a spam text, you can forward it to 7726 (which spells "SPAM"). Most major carriers in the US, like T-Mobile, Verizon, and AT&T, support this.
After you forward the message, you'll usually get an automated reply asking for the phone number it came from. Just reply with that number. This helps carriers identify and shut down spam campaigns faster.
Consider a Dedicated Call Blocker App
For the heaviest spam filters, third-party apps like Truecaller or Hiya itself can be installed from the Google Play Store. These apps maintain massive, crowdsourced databases of spam numbers and telemarketers.
During setup, they'll ask for permission to manage your calls and contacts. Once granted, they can screen every incoming call against their database and show you a name or spam warning even for numbers not in any official directory. They often catch spam that hasn't yet been flagged by the built-in systems.
