How to Block Spam Calls in India
A complete, ordered guide to blocking spam calls and call bombing in India. DND registration, carrier filters, Android call screening, and what to do when calls still get through.
Do these in this order
Order matters more than effort here. The first two steps remove the large majority of unwanted calls with almost no ongoing maintenance. The later steps handle what those two cannot reach. Doing them in the wrong order means maintaining a blocklist by hand for calls that DND registration would have stopped automatically.
- Register on the National Customer Preference Register
- Enable your carrier's verified caller or spam filter
- Turn on Android's built-in Call screening
- Block individual numbers as they appear and screenshot the call log
- Lock down WhatsApp and other apps that expose your number
- Escalate to cybercrime.gov.in if the pattern continues
Step 1: DND registration, the one that matters most
The National Customer Preference Register is the only mechanism in India that suppresses promotional communication across every category, on every operator, from a single submission. It is free, it is statutory, and it is the step that most people skip.
Go to telecomp.in, or use your operator's app, submit your number as a mobile user, and select all categories. Selecting all is almost always correct. The preference takes up to seven days to become fully effective, which is why you should do it now rather than during an attack.
- telecomp.in is the official portal for DND registration
- Select every category unless you specifically want promotional calls
- Effect takes up to seven days, so register in advance
- Service and transactional messages are exempt, so your OTPs keep arriving
- Keep the registration reference number, in case you need to re-verify
Step 2: Your carrier's own spam filter
Every major Indian operator ships a caller identification or spam filtering service in its own app store. These use crowd-sourced reports plus operator-side data, and they are considerably better than a manual blocklist because they generalise from the pattern rather than from the single number.
Enable it, and if your phone number is a secondary or work number, do this on that number too. The filter settings are sometimes buried under a different name depending on the carrier and the app version, so look for caller ID, spam, or verified caller rather than assuming a menu title.
Step 3: Android's built-in call screening
Android has had call screening since Android 11 and it is independent of your carrier. It is reachable at Settings, then Phone app, then Caller ID and spam, then Call screening.
Link a Google account while you are there. With an account linked, numbers that other users have reported as spam are logged automatically rather than only being screened, which means your blocklist improves without you doing anything. You can then screen suspicious calls into your voicemail, or let them through if you want to answer.
Step 4: Block and document as it happens
Screenshot every attack. A timestamped call log is the single most useful piece of evidence you can produce, and it is free to collect. Block the number in the meantime, but do not assume blocking ends it, because the attacker is likely rotating numbers precisely in response to your blocklist.
If the calls are coming from your contacts list, that changes things. A contact calling from an unrecognised number is either a new SIM or an imposter, and both warrant the same caution.
Step 5: When it is not spam, it is fraud
If a caller claims to be from a bank, a police department, a courier or a government department, and they know your name and something else about you, treat it as a probable scam regardless of the caller ID. Legitimate institutions do not call to ask for OTPs, PINs or passwords. Ever.
Hang up and call the number printed on your card or on the official website. Never use a number the caller gave you, and never search for one they gave you either. This single habit prevents most of the fraud that arrives by phone.
Step 6: Escalate when prevention has failed
If calls continue for more than a few days after DND registration and carrier filtering, use the formal route. File at cybercrime.gov.in with your call log screenshots and a description of the pattern, and raise a complaint with your operator to keep the reference number.
Do not be put off by the fact that individual complaints are often closed without action. Complaint volume is the metric that triggers network-level action, so your complaint is not wasted even if that particular case goes nowhere.