The phone messaging service will display a banner alert in the coming weeks prompting users to sign up.
Messaging will be switched off if people don’t accept the changes before the deadline, although calls and notifications will remain for a “short time”.
It comes after an announcement about the update earlier in the year, which sparked panic that it would share more data with its parent company, Facebook.
It caused a stampede away from the tech giant and a sharp spike in downloads of other encrypted messaging service apps.
Now the platform has sought to reassure users that it’s not about to harvest more information but is in response to a new feature which allows purchases and interaction with businesses.
There will be a chance to agree after the deadline and have full functionality restored, but WhatsApp warned that inactive accounts are generally deleted after 120 days.
“To give you enough time to review changes at your own pace and convenience, we’ve extended the effective date to May 15th,” WhatsApp said.
“If you haven’t accepted by then, WhatsApp will not delete your account.”