Feldpost number

During World War II, the FPN usually consisted of five digits.

Six digit codes were used prior to the beginning of the war as exercise post numbers (German: Übungspostnummern), and during it as collective post numbers (German: Sammel-Feldpostnummern) for places with a higher concentration of troops, such as 123 321 for Festung Posen.

The sequence of a Feldpost number did not necessarily mean that the location of the units were at the same area.

The reason behind the FPN was to keep the location of troops and certain divisions secret.

Relatives received the respective FPN of the soldier through messaging cards (German: Benachrichtigungskarten) which allowed for their mail to reach the soldier in the reasonable time of about two weeks.