It's very much appreciated.

[habjan]

Someone wished me on my birthday through electronic media so I replied him " Thank you so much. It's very much appreciated."

was my reply correct.

Thank you so much.

 

[Rover_KE]

Yes, but your question wasn't.

Was my reply correct?

 

[emsr2d2]

Someone [strike]wished me[/strike] sent me good wishes (or "wished me 'Happy Birthday' ") on my birthday through electronic media so I replied [strike]him[/strike] [with] " Thank you so much. It's very much appreciated."

Please see my corrections to. Someone didn't "wish you on your birthday". We don't say "I replied him". "I replied", "I replied with" or "I replied to him" are correct depending on context and the rest of the sentence.