Start date for special handling of New Year's mail

Do you send "nengajo", New Years cards, in Japan? If so, today, December 15th 2025, is the start of the special mail for New Year postcards. Officially the period is from today until December 25th 2025. New Year post cards sent in this period are guaranteed to arrive on New Years Day, January 1st 2026. 

In my experience though, even when I have sent a new years card on December 30th it has arrived on January 1st. However, it is best to respect the official period if you can, because that is the only one that guarantees New Year cards will arrive on January 1st 2026. If you don't mind the cards arriving late, you don't have to worry about the dates. 

A bit of trivia on New Year post: Special handling of New Year's cards began at designated post offices in 1899. Subsequently, special handling was introduced at all post offices in 1905, and the following year in 1906, the system was institutionalized.