How do you reply to a birthday greetings?

Answer 1

Send thank you cards, thanking the sender for thinking of you, and make sure you send them a card on their birthday.

A verbal thank you will do. Only the Greeting card industry and the postal service would want you to send a thank you card for a Birthday Greeting, the recipient who, in turn would feel obligated to return a thank you for the thank you card to which you would have to respond in kind....a never ending cycle of joy for Hallmark I would imagine..