Polite New Year's greeting used from January 1st onward. The phrase literally means 'congratulations on the opening (of the new year)'. It is the standard formal greeting for the new year period.
明けましておめでとうございます。今年もよろしくお願いします。
Happy New Year. I look forward to your continued friendship this year.
新年のご挨拶：明けましておめでとうございます。
New Year's greeting: Happy New Year.
明けましておめでとうございます is spoken (or casually written) year-round-appropriate greeting, while 謹賀新年 is a stiff, formal phrase used almost exclusively on New Year's cards.
明けましておめでとうございます is the full polite greeting, while あけおめ is its casual, shortened slang form used only with close friends.
Standard kanji-kana mixed spelling; the most common written form.
Rare kanji form using 御座います for ございます; mostly seen in formal or traditional contexts.
Very rare full-kanji form; archaic and decorative.
From 明ける (akeru, 'to dawn, to begin') in its continuative form 明けまして (akemashite) + おめでとう (omedetou, 'congratulations') + ございます (gozaimasu, polite copula). The phrase literally means 'congratulations on the beginning (of the new year)'.