1600 Calls Can't Be Blocked: Is Your Phone Safe?

TRAI says calls from 1600 number series — used for transactional alerts like bank OTPs and delivery updates — cannot be blocked even if you are on the DND registry. Only 140-series promotional calls can be stopped via DND registration.

Here's what happened: TRAI clarified that 1600-series numbers are used for transactional and service calls — like bank OTPs, delivery alerts, and appointment reminders — and are exempt from DND blocking.. The 140-series is reserved for promotional calls; registering on the DND registry or using the TRAI DND app can block these unsolicited commercial messages.. Scammers increasingly spoof or misuse number series to impersonate banks and government agencies, making it harder for consumers to distinguish genuine alerts from fraud calls..

What you should do: Register your mobile number on the TRAI DND registry (1909 or the DND app) immediately to block 140-series promotional spam calls.. Never share your OTP, PIN, or Aadhaar details with any caller — even if they appear to call from a 1600-series bank number, as scammers can spoof these.. Report suspicious calls on the Sanchar Saathi portal (sancharsaathi.gov.in) so TRAI can investigate and blacklist fraudulent numbers..

Banks will NEVER call asking for your OTP or CVV — a 1600-series number only means it is service-registered, not that the caller is genuinely your bank. Hang up and call your bank's official number yourself.