When someone wishes you a Happy Birthday, you should reply with "Thanks a lot".
When someone wishes you a Happy Birthday, you should reply with "Thanks a lot".
I would ask them another question, why did they think that?
Thank you very much! (if it's your birthday) I think you have me confused with someone else, it's NOT my birthday. (if it's NOT your birthday)
When someone gives you a birthday wish, it is fine to give a simple thank you as a reply.
Thanks
Thank you.
Thank you? Danke.
Thank you. I appreciate the good wishes.
The reply should be "I'm fine thank you, and yourself"
The correct reply when someone gifts you a "Happy Birthday" is a simple "Thank you." It's not rocket science, just show some gratitude and move on with your day. No need to overcomplicate things, just accept the gift and enjoy your special day.
pleasure