Table of contents
- Why do we receive calls from call centers?
- How to block call centers on Android
- How to block call centers on iPhone
- How to block call centers on landlines
- Method 1: Activate the do not call registry
- Method 3: PBX systems and external filters
- How to identify a call center number
- Protecting yourself from data breaches
- How to avoid being contacted again
- What if your number changes?
Every day, millions of users receive telemarketing calls, unsolicited commercial offers, or automated messages from unknown numbers.
These often persistent calls can come at any time, even multiple times a day, disrupting our routines and invading our privacy. This comprehensive guide explains how to block call centers, how to identify phone scams, and which tools to use to block unwanted calls on iPhone, Android, and landline numbers.
We’ll also cover how to protect your personal data, how to activate the Do Not Call Registry, and which third-party apps are most effective at identifying and blocking call center numbers in real time.
Why do we receive calls from call centers?
Every time you provide your phone number to sign up for a service, newsletter, or promotion, there is a chance that your data will be shared—legally or otherwise—with marketing agencies or call centers. Even just participating in a survey or an online contest may result in your number being added to advertising databases. It’s not uncommon for this information to be sold or transferred to third parties, resulting in an avalanche of unwanted calls.
To make things worse, many unknown numbers can’t be called back, and the caller ID or spam alert is often hidden or missing.
How to block call centers on Android
If you have an Android smartphone, there are several ways to block call centers. The simplest method uses built-in features of the operating system and default dialer app.
Method 1: Block directly from the call log
- Open the Phone app.
- Tap the suspicious or unwanted number.
- Tap the three dots in the top-right corner.
- Select “Block” or “Block contact”.
This allows you to block the call center numbers that have already contacted you.
Method 2: Enable spam filter
Most Android phones include a built-in spam filter.
- Go to Phone > Settings.
- Enable Caller ID and spam.
- Also turn on Filter spam calls.
This way, the system will automatically block numbers identified as call center calls.
Method 3: Use Third-Party Apps
There are many free and paid third-party apps that improve call blocking, such as:
- Truecaller
- Hiya
- Should I Answer?
These apps identify and block telemarketing numbers using user-updated databases.
How to block call centers on iPhone
Apple devices also let you block call centers on iPhone effectively.
Method 1: Manual blocking
- Go to Phone > Recents.
- Tap the “i” icon next to the number you want to block.
- Scroll down and select “Block this Caller”.
Method 2: Silence unknown callers
From iOS 13 onward, you can block unwanted calls from unknown numbers.
- Go to Settings > Phone.
- Enable Silence Unknown Callers.
This feature silences all calls from numbers not in your contacts and sends them directly to voicemail.
Method 3: Use call blocking apps
You can also install apps like Truecaller or CallBlocker, then configure them in:
Settings > Phone > Call Blocking & Identification.
How to block call centers on landlines
Many people still use landlines, which are also vulnerable to telemarketing calls. How can you protect yourself?
Method 1: Activate the do not call registry
On the official website registrodelleopposizioni.it, you can register your phone number, whether mobile or landline. Once registered, it becomes illegal for call centers to contact you without explicit consent.
To register:
- Visit the website and select “Sign Up”.
- Enter the number you wish to protect.
- Confirm with a code you receive.
Tip: Save the toll-free number 800 957 766, which is used to manage or revoke your registration.
Method 2: Phones with built-In filters
Some landline phones have built-in call blocking systems, similar to smartphones:
- Manual blacklist
- Filtering unknown numbers
- Automatic blocking of international numbers
Brands like Panasonic and Gigaset offer these features.
Method 3: PBX systems and external filters
In business or advanced home settings, you can install telephone switchboards or line filters that block call center numbers based on predefined blacklists.
How to identify a call center number
An unknown number isn’t always from a call center, but there are some red flags:
- Suspicious prefixes (e.g., 02, 06, 0874 with odd formats)
- Short calls or calls at strange hours
- No voice or silence on the line
- Overly aggressive or unbelievable offers
Often, numbers may be disguised as mobile or local numbers. In such cases, call blocking is your best defense.
Protecting yourself from data breaches
Many users don’t realize that even interacting with a call center can result in personal data being collected without consent.
To protect yourself:
- Never give your tax ID, IBAN, or passwords over the phone.
- Don’t enter numbers requested by automated calls.
- Avoid confirming your name or address if you’re unsure who you’re talking to.
How to avoid being contacted again
Besides blocking calls, prevention is key:
- Don’t agree to marketing consents during online signups.
- Avoid answering telephone surveys.
- Don’t post your phone number on public websites or social media.
What if your number changes?
Even if you change SIM cards or operating systems, your protection can continue:
- On Android: Apps like Truecaller link to your Google account.
- On iPhone: Blocks are saved directly on your phone.
- On landlines: The Do Not Call Registry is tied to your number, so you’ll need to register again if you change providers.
Conclusion
Blocking call centers is possible—on Android, iPhone, and even landlines. With just a few steps, you can stop unwanted calls, protect your personal data, and reduce constant disruptions.
Thanks to tools built into operating systems, the Do Not Call Registry, and powerful third-party apps, you can effectively defend yourself against aggressive telemarketing tactics.
Questions and answers
- How do I block call centers on Android?
Enable Caller ID and spam protection in settings, or use apps like Truecaller. - How do I block call centers on iPhone?
Use “Silence Unknown Callers” or block contacts manually. - What does the Do Not Call Registry do?
It prevents call centers from contacting you without your permission. - Can I block unknown numbers?
Yes, both Android and iPhone allow you to silence or block them. - How can I tell if a number is a call center?
Strange prefixes, silent calls, or overly aggressive offers are red flags. - Can landline phones block calls?
Some models can, or you can use external devices or register with the Do Not Call list. - What if my phone number changes?
You’ll need to repeat the registration process, including for the Do Not Call Registry. - Are call blocking apps safe?
Yes, especially trusted ones like Truecaller and Hiya. - Can call centers bypass blocks?
Sometimes, by changing numbers. Updated blacklists help fight back. - Is 800 957 766 used to block call centers?
It’s the customer support number for Italy’s Do Not Call Registry to manage your subscription
