The German Post Offices Abroad were a network of post offices in foreign countries established by Germany to provide mail service where the local services were deemed unsafe or unreliable. They were generally set up in cities with some sort of German commercial interest. In the earliest period when such offices were open, stamps used there can only be identified by their cancellations. Such stamps are known as forerunner (Vorläufer) stamps. Later stamps issued for use at a post office abroad can generally be identified by overprints even when not postally used. Germany began issuing distinctive stamps for use overseas beginning in the late nineteenth century, and the number and variety of issues reached its heyday at the beginning of the twentieth century. All German Post Offices Abroad were closed down during or shortly after World War I.
German post offices in China (Deutsche Post in China) started to operate in 1886. Initially definitive stamps were used without overprint; such a stamp used in China is only recognizable by its cancellation. In March 1898, six stamps were issued with a 45-degree diagonal overprint reading China. In December 1898, the same six stamps were reissued featuring a 56 degree diagonal overprint. The December stamps are listed in the Scott catalogue as #1-6 while those from March are given subscript numbers (Scott #1c, 1d, 2a, 3a, 4a, 5a, and 6a). These are all usually found with Shanghai cancels.
From 1900 onwards, stamps of the Germania definitive series were issued with new style of horizontal China overprint. After 1905, a third “Gothic” style of China overprint was applied to Germania stamps which also obliterated the stamps’ face value as stated in German mark and pfennig values, and replaced them with equivalent face values in Chinese dollars and cents. All German post offices in China closed after China declared war on Germany on March 16, 1917, if they were still operating on that date. Some had closed prior to this.
During the Boxer rebellion (1900–01), ten military mail offices were maintained. Disruptions in stamp supplies and postal operations caused by fighting at this time led to unoverprinted German stamps and stamps from the German colony of Kiautschou being used at these military offices as well as at the German post offices open to civilians. Such uses occurred primarily, but not exclusively, at Peking, Tientsin, and Shanghai. The unoverprinted German and Kiautschou stamps used at any of these offices are referred to collectively as Petschili issues.
Stamps printed for use in the German post offices in China but with a bilingual cancel reading TSINGTAU-KIAUTSCHOU or TSINTAU CHINA in the period 1898-1901 are actually forerunners of Kiautschou Pachtgebiet, which did not issue distinctive stamps of its own until early 1901.