How does WhatsApp handle phone number portability and account migration?

[muskanhossain]

WhatsApp handles phone number portability and account migration through a specific set of procedures designed to ensure a smooth transition for users while maintaining the integrity and security of their accounts. Here's a breakdown of how it works:

Phone Number Portability (Changing Phone Number)
WhatsApp allows users to change the phone number associated with their account. This is useful when a user gets a new phone number but wants to keep their existing WhatsApp account, including their cambodia whatsapp number data chats, groups, and profile information. The process differs slightly depending on whether the user is using the same phone or a new phone.

On the Same Phone:

Insert New SIM: The user first inserts the SIM card with their new phone number into their current phone.
Change Number Feature: Within the WhatsApp app, they navigate to Settings > Account > Change number.
Enter Old and New Numbers: They enter their old phone number in the first field and their new phone number in the second field, both in full international format.
Notification (Optional): WhatsApp allows the user to notify their contacts about the number change. They can choose to notify all contacts, contacts they have chats with, or specific contacts. Group chats are always notified.
Verification: The user is then prompted to register their new phone number via SMS or phone call, similar to the initial account setup.
On a New Phone:

Backup (Old Phone): Before changing the number on the old phone, WhatsApp recommends creating a backup of the chat history using Google Drive (on Android) or iCloud (on iOS).
Change Number (Old Phone): The user performs the "change number" process on their old phone as described above. This transfers account information to the new number on WhatsApp's servers.
Install and Register (New Phone): On the new phone, the user installs WhatsApp and registers their new phone number.
Restore Backup (New Phone): During the registration process on the new phone, WhatsApp will prompt the user to restore their backup from Google Drive or iCloud, transferring their chat history to the new device associated with the new phone number.
Account Migration (Changing Phones with the Same Number)
If a user gets a new phone but retains the same phone number, the process is simpler:

Backup (Old Phone): Create a backup of the chat history on the old phone.
Install and Register (New Phone): Install WhatsApp on the new phone and register the existing phone number.
Restore Backup (New Phone): Restore the backup during the registration process to transfer chat history and account information to the new phone associated with the same number.
Key Considerations:
International Format: WhatsApp requires phone numbers to be entered in full international format (e.g., +[Country Code][Phone Number]).
Verification: The new phone number must be able to receive SMS or phone calls for verification.
Unsupported Numbers: VoIP, toll-free, premium, and landline numbers (except on WhatsApp Business) are typically not supported for registration.
No Reversal: If the "change number" feature is used in error, the change cannot be reversed.
Blocked Contacts: Blocked contacts remain blocked after a number change.
Group Notifications: Group chats are always notified when a phone number is changed within them.
WhatsApp's system is designed to link a user's account and associated data primarily to their phone number. The "change number" feature effectively migrates this link to a new phone number, while account migration to a new device with the same number re-establishes the existing link on the new device using backups. This ensures continuity of service and data for users when they change phones or phone numbers.