Stop Spam Calls in India: DND, Filters and Complaints

In short

Dial 1909 (toll-free) or use the TRAI DND app to sign up for DND; your OTPs and other transactional SMS will keep arriving. Next, switch on spam protection in your phone. If a sales call or SMS still slips through, complain within 7 days using 1909, your operator’s app or the TRAI DND app. Fraud attempts go to Chakshu (Sanchar Saathi), and if money has already gone, ring 1930.

Spam is best handled in layers, because each layer catches something the others miss. DND keeps registered telemarketers away, your operator and handset label a good share of what remains, and complaints get action taken against the senders who keep breaking the rules.

Spam calls are rarely the reason people walk into Mobivault. The subject usually comes up while we are setting up someone’s new phone.

Jump to a section8 sections

Sign up for DND, TRAI’s Do Not Disturb register
Who is really calling? Number series, SMS headers and caller names
Let your operator flag spam on the network
Switch on your phone’s own spam filters
Raise a complaint so the sender faces action
Send fraud attempts to Chakshu
Common questions
References

TRAI’s formal name for DND is preference registration. It lets your operator know which kinds of commercial calls and SMS from registered senders (140-series numbers and SMS headers ending in -P, for example) you would rather not get. Your choice can be changed whenever you like.

From the number you want to protect, dial 1909 and go through the voice menu.
Prefer an app? Get TRAI DND for Android or iPhone, confirm your number with an OTP, then block every promotion or just the categories you pick.
Your operator’s own channels work too. In MyJio go to Profile → Settings → Service settings → Do not Disturb; Vi customers can use the Vi app or myvi.in/dnd; Airtel offers a DND page on airtel.in that works with an OTP.
Hold on to the confirmation SMS, since it carries your reference number.

How fast does it kick in? Jio says within 24 hours. Vi’s code of practice promises to acknowledge your request within 15 minutes and put it in place within 24 hours.

Note: Texting 1909 is another route. The messages listed in TRAI’s rules are BLOCK PROMO for every promotion and BLOCK 1 to BLOCK 8 for a single category each. Operator help pages, however, still mention older keywords: START 0 appears on Jio’s help page and Airtel’s blog, while Vi’s FAQ gives FULLY BLOCK. When in doubt, just call 1909.

Picking the right DND setting

Setting	Blocked	Still allowed
Block Promo	Promotional calls and SMS across all categories	Government, service and transactional messages
By category (1 to 8)	Promotions in just the categories you choose	All other calls and messages
Fully Block (being withdrawn)	Every promotional call and SMS, along with service messages you had consented to	OTPs and other transactional messages, government messages, and service messages from companies you already have a relationship with

Checked 10 October 2026 against the Second Amendment Regulations, 2025 and the Third Amendment Regulations, 2026 to TRAI’s TCCCPR.

Fully Block is on its way out. TRAI’s Third Amendment, notified on 18 September 2026, scraps this option. The change takes effect 30 days after the amendment appears in the Official Gazette, and from then on operators get 15 days to shift every Fully Block registration over to Block Promo. There is nothing you need to do: Block Promo still keeps all promotions out while letting service messages in.

Promotions are grouped into eight categories: banking, insurance and credit cards; real estate; education; health; consumer goods and automobiles; communication, broadcasting, entertainment and IT; tourism and leisure; food and beverages. Blocking can also be set by mode (calls, SMS, robocalls), by the time of day and by the day of the week.

Tip: Missing OTPs are never caused by DND, since no DND setting blocks them; for that problem, read our guide on OTP SMS that never arrive. Every promotional SMS must also include a way to opt out, and once you opt out of a sender, it cannot come back asking for your consent for 90 days.

Who is really calling? Number series, SMS headers and caller names

The number or header on your screen says a lot about who sent it and whether DND can stop it.

On your screen	Meaning	Blocked by DND?
A call from a 140xx number	A registered business making a promotional call	Yes, in the sectors you have blocked
A call from a 1600xx number	A service or transactional call from a bank or NBFC, an insurer, a broker, a mutual fund, a pension fund or a government body	No
A call from a 1601xx number	A service or transactional call from a courier or logistics company or a utility (water, electricity, gas or LPG); this series has been rolling out since August 2026	No
An SMS header with -P at the end	A promotional SMS	Yes
An SMS header with -S at the end	A service SMS	No, unless you are on Fully Block (which TRAI is withdrawing); only that option stops service messages sent because you gave consent
An SMS header with -T at the end	A transactional SMS, an OTP for example	No
An SMS header with -G at the end	A message from the government	No

Compiled from TRAI regulations and press releases; checked 10 October 2026.

TRAI gave insurers, mutual funds, pension entities, banks, NBFCs and qualified stockbrokers deadlines falling between 1 January and 15 March 2026 to shift their service and transactional calls onto 1600 numbers. That makes any caller on an ordinary 10-digit number who claims to be from your bank or insurer worth extra suspicion. Never give out an OTP during a call.

In July 2025, COAI, the body representing the operators, said every operator had rolled out the header suffixes -P, -S, -T and -G. You can look up the company behind any header on TRAI’s portal, smsheader.trai.gov.in.

The caller’s name on screen (CNAP)

CNAP, short for Calling Name Presentation, displays the caller’s name with no app involved. TRAI’s recommendation is to use the name given on the caller’s SIM application form. DoT’s view, which TRAI noted in October 2025, is that the feature should be switched on by default, with the option of asking your operator to switch it off, and that 4G and 5G users should get it first.

Operator pilots were reported in the trade press in November 2025, and since then operators have been enabling CNAP in phases. According to Vi’s help page, on Vi it needs a VoLTE phone and, for the moment, works only for calls coming from other Vi numbers. As of October 2026 we had not found any official statement that it works on all networks or across operators. Read the name as a clue, not a safety check: it tells you whose name the SIM is registered in and nothing about whether the call is safe.

Let your operator flag spam on the network

TRAI said in September 2026 that the major operators now run AI-based systems that spot suspected spam and warn customers about it. In most cases you just get a warning label, and picking up is still your call.

Airtel: calls and SMS that look like spam have carried a “Suspected SPAM” mark since September 2024. According to Airtel the service is free and active for every customer, without any app or request, and it also warns you about harmful links in SMS.
Vi: the Vi Protect page states that the network automatically marks suspected spam calls “Suspected SPAM” and SMS “Vi Suspected SPAM”, at no extra cost. Call alerts need a VoLTE phone, while SMS flagging works on any handset. The Vi app also lets you report and block spam calls.
Jio and BSNL: we could not find an official page that explains a spam label on their calls. In October 2025, news reports said Jio had begun rolling out spam alerts on incoming calls; in August 2025 BSNL announced its network had started blocking suspicious SMS links, with no setting for you to switch on.

According to TRAI, calls from its official 140 and 1600 series are not to be tagged as spam. Once in force, its September 2026 amendment also stops operators’ AI systems from flagging 140xx, 1600xx and 1601xx numbers.

Switch on your phone’s own spam filters

Android with the Phone by Google app

In the Phone app, tap More options (three dots) → Settings → Caller ID and spam.
Make sure See caller ID and spam is switched on. It is on by default.
Switch on Filter spam calls. Filtered calls won’t ring or leave a missed-call alert, though you will still find them in your call history. If your phone has automatic Call Screen, look for spam blocking inside Call Screen instead.

For text messages, open Google Messages, tap your profile picture → Messages settings → Protection and safety → Spam protection, and confirm that Enable spam protection is on. Google switches it on by itself on phones that support it.

Samsung Galaxy

In the Phone app, tap the three dots, then Settings.
Switch on Caller ID and spam protection, then tap Agree.
Tap Caller ID and spam protection again, switch on Block spam and scam calls, and choose either Block all spam and scam calls or Only block high-risk scam calls.

Samsung India’s Smart Call page likewise sends you to Caller ID and spam protection in call settings. We took the names of the two blocking options from Samsung’s Canada guide, so the wording on your particular model or One UI version may be a little different.

iPhone

Calls from numbers you don’t know: open Settings → Apps → Phone. On iOS 26 or later, set Screen Unknown Callers to Silence; on iOS 18, switch on Silence Unknown Callers. Such calls are sent to voicemail and still show up in Recents.
Spam calls: on that same screen, switch on the Spam filter (called Silence Junk Callers on iOS 18). It acts only on calls your carrier marks as possible spam. We found no confirmation that any Indian operator supplies this to iPhones, so don’t depend on it.
Text messages: on iOS 26 or later, open Messages, tap the filter button → Manage Filtering and switch on Screen Unknown Senders. So that OTP alerts still reach you, tap Allow Notifications and switch on the categories you need (the choices depend on your region). On iOS 18 the setting lives at Settings → Apps → Messages → Filter Unknown Senders. With Text Message Filter on, SMS from unknown senders are also sorted into Transactions and Promotions.

Warning: When you silence unknown callers, real calls get caught too, for example from a delivery agent or a clinic. Save the numbers you expect to hear from, and look through your spam folder from time to time.

At Mobivault we find that silencing unknown callers suits older parents best. Customers who get lots of calls from new numbers, shopkeepers for instance, have ended up missing real calls with it switched on. Use it only if your important calls mostly come from people already in your contacts.

Truecaller and other caller ID apps

Apps of this kind label spam based on what their own users report. Before you install one, look at the permissions it asks for, such as access to your contacts or call log, and go through its privacy policy. Under TRAI’s rules these apps may not tag or block 140 and 1600 numbers, although you remain free to block any number on your own.

Blocking one number at a time

Phone by Google: tap the call in your call history and choose Block / report spam. To undo it, go to Settings → Blocked numbers. The Unknown switch on that screen only blocks private or hidden numbers.
Samsung: Phone app → three dots → Settings → Block numbers, then enter the number or choose it from Recents or Contacts. While a call is coming in, you can also tap Block number.
iPhone: in Phone → Recents, tap the info button beside the number and choose Block Caller. Messages and FaceTime calls from that number are blocked as well. To reverse it, find Blocked Contacts in Settings (where it sits depends on your iOS version).

A block keeps only that one number away. Spammers simply move to new numbers, which is why a complaint is worth filing as well.

Raise a complaint so the sender faces action

TRAI revised its complaint rules in February 2025, and every change listed here has been in force since mid-April 2025:

You now get 7 days: the window to complain is 7 days after the call or SMS, up from 3. Anything filed later only counts as a report.
Unregistered senders, no DND required: telemarketers are not allowed to use regular 10-digit numbers, so a sales call from an ordinary mobile number can be complained about even if you never registered on DND.
Registered senders, DND first: promotions from 140 numbers and -P headers are permitted unless you have blocked that category on DND, so register before you complain.
What a valid complaint includes: the sender’s number or header, your own number, the date and a brief description.

Call 1909, or open the TRAI DND app or your operator’s app or website and pick the spam (UCC) complaint option.
Select the call or SMS from your log, or upload a screenshot (operator apps have to support this), and check the details.
Submit it and note down the complaint ID so you can follow its progress.

Under the 2025 rules, if 5 different people complain about an unregistered sender within 10 days, action begins: the operator suspends the sender’s outgoing services while it investigates. A sender found at fault loses all outgoing services for 15 days the first time, and repeat offenders have every connection cut for a year and are blacklisted.

Two more changes come from TRAI’s Third Amendment, notified on 18 September 2026. Action will be able to start after complaints from just 3 different people within 10 days, provided at least one of the sender’s numbers has also been flagged by the operator’s AI. You will also be able to appeal the outcome of a complaint within 15 days of being told the result (or, if 15 days pass with no result, within the following 15 days), using the same channels you complain through. Neither change applies yet: both start 90 days after the amendment is published in the Official Gazette.

Send fraud attempts to Chakshu

Fraud means someone is trying to cheat you. Typical examples are fake KYC or bill-payment messages, callers pretending to be police, CBI, TRAI or DoT, fake customer care, job or loan offers, investment scams and sextortion. These belong on Chakshu, a Department of Telecommunications (DoT) service hosted on Sanchar Saathi.

Go to sancharsaathi.gov.in/sfc or open the Sanchar Saathi app, which lets you report directly from your call log or SMS.
Select call, SMS or WhatsApp, pick the fraud category and add a screenshot.
Fill in the number or SMS header, the date and time (it must fall within the last 30 days) and a description of 30 characters or more.
Give the number the call or message came to, confirm it with an OTP, accept the declaration and submit.

DoT says it cannot share the outcome of individual reports. For WhatsApp, report the sender inside the app as well. Sanchar Saathi is also the place to block a phone that has been lost or stolen.

Warning: Chakshu does not deal with money you have already lost. If you’ve been cheated, ring the cyber crime helpline 1930 or file a report at cybercrime.gov.in right away, and contact your bank.

Shop-floor note: If spam calls are wearing you down, bring your phone in. We will register your number on DND with you, either by calling 1909 or through the TRAI DND app, and switch on the phone’s spam filter before you head home.

Common questions

Does DND block OTPs or alerts from my bank?

No. OTPs and other transactional messages get through whichever DND option you choose.

Why do spam calls keep coming after I signed up for DND?

Because DND only governs registered senders. A sales call from a normal 10-digit number already breaks the rules, so complain about it within 7 days and switch on your phone’s spam filter. A new registration may also need as long as 24 hours before it takes effect, and businesses you have given digital consent to are still allowed to send you promotions.

Is DND registration required before I can complain?

Only for promotions from registered senders, where you must block that category on DND first. Complaints against unregistered senders don’t need it.

Is there a way to block government SMS?

No. TRAI’s rules let government messages (headers ending in -G) go out without consent, and DND offers no setting that blocks them.

A fraud call has already cost me money. Is Chakshu where I report it?

No, Chakshu is meant for fraud attempts. Call 1930 or report at cybercrime.gov.in at once, and phone your bank.