Hey Tiago, how are you? If you are to wish someone 'a' happy new year, then you should place the article ''a'' in front of ''happy new year.'' Furthermore, you may either say ''Happy New Year'' or ''I wish you a Happy New Year.'' Both ways should befit quite perfectly to your intention! Hope that helps!!!

The latter

the correct is i wish you a happy new year

the correct is i wish you a happy new year

Thanks, Tika. I always get confused about it :D! Btw, I wish you a happy new year :D