SIM swap and e-SIM fraud

If your phone unexpectedly shows "No service" for long while others on the same network are fine, treat it as an emergency.

How it works

Your mobile number is the key to your bank OTPs, UPI and most password resets. In a SIM swap, the fraudster persuades or tricks the telecom system into moving your number to a SIM he holds.

By tricking you. A caller from "your mobile company" offers a free upgrade to 4G, 5G or e-SIM, or says your SIM will be blocked. He asks you to forward a text, send a code by SMS, or read out the code you receive. That code authorises the change. For e-SIM he may ask you to register his email address on your number or to share the QR code sent to you.
By impersonating you. With forged identity papers, someone asks a store for a replacement SIM in your name, claiming the old one is lost.

When the swap completes, your SIM goes dead. Calls and OTPs now reach the fraudster, who resets passwords and drains accounts, usually at night or over a weekend so that you notice late.

Warning signs

Sudden loss of network that does not return after restarting the phone, while people around you on the same network have signal.
Messages from your operator about a SIM change, e-SIM activation or porting request you did not make.
A caller pressing you to send an SMS or share a code "to upgrade your SIM".
A flood of calls or messages at an odd hour (sometimes used to make you switch the phone off or miss the operator's alert).
Alerts of logins or password resets you did not start.

What to do within minutes

From another phone, call your mobile operator's customer care or go to its store with identity proof. Say you suspect a fraudulent SIM replacement and ask them to block it and restore your number.
Call your bank's helpline and ask for a temporary block on debits, cards and UPI.
If money has gone, dial 1930 and follow "If money has already gone" below.
Change the passwords of your email and main accounts from a trusted device, and check their recovery phone and email.

Reducing the risk

Never forward a text, send an SMS or share a code because a caller asked. Your operator will not ask.
Do SIM upgrades and e-SIM conversions only in the operator's own app or store.
Check which mobile connections exist in your name using the "Know Mobile Connections in Your Name" service of the government's Sanchar Saathi portal, and report any you did not take. See Sanchar Saathi.
Put a SIM PIN on your SIM so that it cannot be used in another phone without the PIN: on Android under Settings › Security › SIM lock, on iPhone under Settings › Mobile Service › SIM PIN. Learn your operator's default PIN from its official help pages first; three wrong tries lock the SIM.
Use an authenticator app or passkeys for email and other accounts, so that the phone number alone cannot reset them. See two-step verification.
Keep email alerts switched on at your bank as well as SMS, so that a warning reaches you by a second route.

My phone lost signal for an hour. Was it a SIM swap?

Usually it is only a network fault. Restart the phone, ask someone on the same network, and if the signal does not return or you see messages about a SIM change, call the operator at once.

Does an e-SIM make me safer or less safe?

An e-SIM cannot be physically stolen, but it can still be moved by fraud if you share the codes. The same care applies.

If money has already gone

Dial 1930 at once. It is the national helpline for victims of financial cyber fraud. Give the transaction details; the earlier the report, the better the chance that the money can be held before it is moved on.
Call your bank or card company on its official number and block the card, UPI or account. Report the transaction as unauthorised and note the complaint number.
File the complaint on the National Cyber Crime Reporting Portal, cybercrime.gov.in, and keep the acknowledgement number.
Keep everything: screenshots, numbers, UPI IDs, account numbers, transaction references, links, the app's name. Do not delete chats.

The full checklist, with what to keep ready, is on what to do after a fraud. Helpline and portal checked on 12 November 2026.

Independent guide. This is not a government, bank or police website. Helplines and rules were checked at official sources on 12 November 2026; confirm on the official site before relying on them.