• Firstly you should the person you are sending use whatsapp payment method or not.
• If you are unable to add a bank account because it is not listed, check to see if your bank supports UPI. Check that your WhatsApp number and the phone number associated with your bank account are the same if you're having trouble adding your bank account. If not, get in touch with your bank.
• Unable to send payment: If your contact does not have payments enabled, you will be unable to send money. When you try to send them money, you'll get the following message: To receive a payment, [contact name] must go to WhatsApp Settings > Payments and enable payments.

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