Somewhere in India, a SIM card has retired to a drawer while its WhatsApp account keeps chatting on a different phone. That quiet arrangement now has an end date.

The short answer: yes, WhatsApp can stop working if the number on your account is not on a SIM inside the phone running the app. India's telecom department has ordered eight messaging apps to stay continuously linked to that SIM, and the government has told Parliament the compliance date is 31 December 2026. If your registered SIM already lives in your phone, you should barely notice.

What the rule says

The Department of Telecommunications issued the directions on 28 November 2025. They name WhatsApp, Telegram, Snapchat, Arattai, ShareChat, Josh, JioChat and Signal, and they cover apps that use an Indian mobile number to identify users. The app must become unusable "without that specific, active SIM," in the department's words.

The reason is a gap in how these apps work. They verify your number at setup and then stop asking. The department says accounts keep running after a SIM is removed, deactivated or taken abroad, which helps scammers run digital-arrest calls on Indian numbers from overseas. It puts 2024 cyber-fraud losses above ₹22,800 crore.

Banking and UPI apps already bind to the SIM, which is why your payment app turns suspicious the moment you swap phones. Messaging is being pulled into the same regime.

What has changed since the order

• The deadline moved. The order first gave apps 90 days. A minister's written reply on 2 April 2026 set 31 December. Reports from late October put the operational start at 1 January 2027, which is simply the morning after.
• The six-hour logout softened. Web sessions were to end every six hours at most. The same reply says logout now depends on a risk-based analysis, with no fixed period. MediaNama reported on 16 October that no revised written direction had appeared, so treat this as the government's stated position.
• Testing has started. Meta confirmed to MediaNama in April that it was testing SIM binding with regular Indian users. One user's screenshot showed WhatsApp asking for phone permission to check the number on the SIM.
• The apps are at different stages. CNBC, as cited by MediaNama, reports that Apple has changed iOS to support the rule, Signal has not answered government notices, and Snapchat says the rule does not apply because phone numbers are not its main identifier. WhatsApp and Arattai say they are working to comply, while Telegram has not clarified, Inc42 reports.

Will your setup survive?

What the order implies for common setups

Your setup	Likely result	How firm is that?
Registered SIM in the phone running the app	Works, after a permission prompt	Follows the order
Roaming abroad, SIM still in the phone	Works	Stated by the department
Indian SIM out, local SIM in, on Wi-Fi	Access lost	Internet Freedom Foundation's reading
Account on a phone whose SIM is elsewhere	Blocked until the SIM returns	Follows the order
WhatsApp Web or desktop	Works, with risk-based logouts and QR re-linking	Minister's reply; written text pending
Linked second phone or tablet	Unknown	The order is silent
Dual-SIM phone	Should work if the registered SIM is one of the two	Unconfirmed
eSIM	Should count as a SIM	One report says yes; Inc42 says unclarified

Early beta builds limited the check to +91 accounts, Digit reported in February, so accounts on foreign numbers should be unaffected. Non-resident Indians who keep a +91 account without that SIM are the awkward case.

If a check fails, the same report expected restricted access until you verify again, with chats intact. That comes from beta builds, not a WhatsApp promise.

A worked example

Meera is hypothetical. Her WhatsApp runs on an old Airtel number, but that SIM sits in a hotspot at home and her phone holds a Jio SIM. On the order's wording, that setup fails. She has two fixes.

One: move the Airtel SIM into her phone's second slot, assuming dual SIM is accepted. Two: switch her account to the Jio number. WhatsApp says Change Number carries over her profile, settings and chats. Cloud backups made under the old number can no longer restore, so she should make a fresh one straight after.

Five things to do before 31 December

1. Check the number on each app. Open your profile in WhatsApp, Telegram and Signal. Is that SIM in this phone?
2. Fix any mismatch. Move the SIM, or use Settings, Account, Change number on your primary phone. The new number must be able to receive an SMS or call.
3. Keep that SIM alive. A deactivated number fails just as a removed one does. Recharge the prepaid line you forgot about.
4. Sort out travel first. Leave the Indian SIM in and roam, or add a local eSIM beside it. Our travel eSIM guide covers costs and compatibility.
5. Treat any "verify your SIM" message as a scam. The real check appears inside the app. Expect fraudsters to borrow this deadline, just as they borrow fake delivery alerts.

Selling on WhatsApp? Try a normal working day with the registered phone in the shop, not at home. In a CUTS International survey of 600 small businesses, 58% used web interfaces and 63% ran multi-device workflows, so a surprise logout could land mid-order.

Will it actually stop fraud?

The government's case is traceability: every active account tied to a live, identity-verified SIM. The Internet Freedom Foundation doubts it, arguing that scammers often get SIMs on borrowed or forged IDs and then discard them. It has asked for the order to be recalled.

The cost lands on ordinary households too. About 86% of the people CUTS surveyed let family members use their phone or SIM for messaging. Nobody can measure the fraud benefit until the check is live, so for now the honest verdict is plausible, unproven and inconvenient.

So find out tonight which SIM your WhatsApp thinks it lives in. If the answer is a drawer, you have until New Year's Eve to go and get it.