I am unable to subscribe. Refer Pop up message on screenshot for details

Sign out and sign again or change payment method

Had done same too but unable to subscribe. 

Thank you for what you said. 

contact with support team

Hi ​@Veloxdrops_G,

That error message you see is consistent with the error message that appears when attempting to pay using a card issued by the Bank of India. Are you using a card issued by that bank, by chance? If so, you’ll need to use a different card, as Klaviyo cannot accept payments via cards issued by the Bank of India at this time. Apologies for the inconvenience, and let me know if this is not the issue!