the pdf states: The document number always begins with a letter
Format
9 to 11 characters
Pattern
one letter in C, F, G, H, J, K (case insensitive)
eight digits or letters in C, F, G, H, J, K, L, M, N, P, R, T, V, W, X, Y and Z (case insensitive)
optional check digit
Optional d/D
Character [1–9] is a digit from [0–9] or an alphanumeric character from [A-Z] except ABDEIOQSU.
Character 10 is a digit from [0–9].
Character 11 is an optional character that starts with the letter 'D'.
Checksum: ??
I can't find a source for checksum, my best guess is its the same 7 3 1 pattern as National ID. You seem to have better luck finding documentation.
https://learn.microsoft.com/en-us/microsoft-365/compliance/sit-defn-germany-passport-number?view=o365-worldwide https://en.wikipedia.org/wiki/German_passport https://www.bmi.bund.de/SharedDocs/downloads/DE/veroeffentlichungen/themen/moderne-verwaltung/ausweise/personalausweis-seriennummer.pdf?__blob=publicationFile&v=15
the pdf states:
The document number always begins with a letter
Format 9 to 11 characters
Pattern one letter in C, F, G, H, J, K (case insensitive) eight digits or letters in C, F, G, H, J, K, L, M, N, P, R, T, V, W, X, Y and Z (case insensitive) optional check digit Optional d/D
Character [1–9] is a digit from [0–9] or an alphanumeric character from [A-Z] except ABDEIOQSU. Character 10 is a digit from [0–9]. Character 11 is an optional character that starts with the letter 'D'.
Checksum: ??
I can't find a source for checksum, my best guess is its the same
7 3 1
pattern as National ID. You seem to have better luck finding documentation.