Established in 1874 as the General Postal Union, the UPU is among the oldest extant intergovernmental organizations. It sought to standardize international mail delivery by establishing a uniform postal rate and equal treatment between domestic and foreign mail. The organization adopted its current name in 1878.

The undersigned plenipotentiaries of the Governments of the countries which have to-day signed the treaty concerning the formation of a General Postal Union, have agreed as follows:

The Universal Postal Union is a United Nations specialized agency and the postal sector's primary forum for international cooperation.

万国邮政联盟 （法语： Union postale universelle；英语： Universal Postal Union； 缩写： UPU）， 简称 万国邮联，是 联合国 协调 会员国 （英语：Member state） 之间 邮务 政策 的 专门机构，也是世界性的 邮政 国际组织，总部设于 瑞士 伯恩。 万国邮联每个 会员国 （英语：Member state） 均同意并接受在相同的条件下处理国际间的邮务、邮政职责。

On 9 October of the same year – a day now celebrated throughout the world as World Post Day – the Treaty of Bern, establishing the General Postal Union, was signed. Membership in the Union grew so quickly during the following three years that its name was changed to the Universal Postal Union in 1878.

Established in 1874, the Universal Postal Union (UPU), with its headquarters in the Swiss capital Berne, is the second oldest international organization worldwide. With its 192 member countries, the UPU is the primary forum for cooperation between postal sector players.

伯爾尼條約（法語： Traité de Berne ；英語： Treaty of Bern ），全称關於成立郵政總聯盟的條約（法語： traité concernant la création d’une Union générale des postes ；英語： Treaty concerning the formation of a General Postal Union ），於1874年簽署。

The Treaty of Bern (formally the Treaty concerning the formation of a General Postal Union), signed on 9 October 1874, established the General Postal Union, which is today known as the Universal Postal Union.

formation of a general postal union. signedatberne, october 9, 1874. washington: government printing office 1875.

2025年2月12日 · Universal Postal Union (UPU) 1874: established by the Treaty of Bern as the General Postal Union; 1878: renamed Universal Postal Union; Relationship Agreement with UN (1948) 19 UNTS...