International Mail Day

What Is International Mail Day?

Every January 8th is "International Mail Day" (外国郵便の日, Gaikoku Yūbin no Hi) in Japan. On January 8, 1875, the Yokohama Post Office (横浜郵便局, now the Yokohama Central Post Office) held the opening ceremony for Japan's first international mail service — marking the moment Japan joined the global postal network. The service was made possible by Japan's accession to the General Postal Union (the predecessor of the Universal Postal Union) in 1877, though actual mail exchange with foreign countries had begun earlier through bilateral arrangements. International mail connected Japan to the world and was essential to the expansion of Japan's international trade and diplomacy.

Japan's Entry into the Global Postal Network

The opening of international mail service from Yokohama in 1875 came six years after the domestic postal system was established (1871). Yokohama, as Japan's primary port for international trade, was the natural starting point for international mail — letters and packages bound for Europe, America, and Asia were routed through Yokohama's port to steamships and onward through the emerging global postal network. The efficiency with which mail could now travel between Japan and the wider world was a significant factor in the expansion of Japan's export trade, particularly in silk and tea.

The Universal Postal Union

Japan joined the General Postal Union (which became the Universal Postal Union in 1878) in 1877 — one of the early members of what is now the world's second-oldest international organization. UPU membership guaranteed that Japanese mail would be handled by foreign postal systems under standardized rules and at agreed rates, making reliable international postal communication genuinely practical for the first time.

International Mail Today

Japan Post continues to operate one of the world's most reliable international mail services, with competitive rates and extensive global coverage through UPU agreements. The growth of international e-commerce has transformed the scale of international parcel shipping — Japanese consumers buying goods from overseas and Japanese small businesses selling to global customers generate enormous volumes of cross-border packages that move through the postal network Japan built in 1875.

Fun Facts

• Aerogramme: The aerogramme — a lightweight sheet that folds into its own envelope for air mail — was a mid-20th century innovation that made international correspondence more affordable, and Japan Post was an early and enthusiastic issuer of aerogramme sheets with distinctive Japanese designs.
• EMS: Japan Post's EMS (Express Mail Service) international parcels are known for their reliability and tracking capabilities, and are particularly popular among international buyers of Japanese goods through platforms like Yahoo! Auctions Japan.