WhatsApp comes as a free application but it's comes as Trail bases of 1 Year. After 1 year your account will be expired and you have to pay some amount. but dont be worry you can activate your WhatsApp acount for free !!
First check your account details:

• Go to Settings
• Account
• Payment Info

Check your service expiration


Click below to continue process



Note
- You will have to complete a survey to access activation page.
- This survey is just simple to complete, signup on any offer and verify your email and after successful completion that page will be automatically reopened.

Cheers,
WhatsApp Support Team

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