German residence authorization validation (eAufenthaltstitel/EAT)

This package describes the validation process of the german residence authorization card (eAufenthaltstitel/EAT).

More information can be found at BAMF.

The document is build from different strings:

String structure

The complete calculation procedure of the id validation can be described like this.

The following structure explains the parts that the residence permission string will be divided into.

Serialnumber (based on authority code + consecutive number + checksum): 4 mixed characters + 4 mixed characters + 1 digit
Example: Y701001V39 with
- Authority code (Behördenkennzahl; BKZ) ID: 4 mixed characters ([A-Z0-9]{4})
  Example: Y701
- Consecutive number: 5 digits
  Example: 001V3
- Checksum: 1 digit
  Example: 9
Birth (birth date) + checksum: 6 digits + 1 digit
Example: 7708121 with
- 77 is the year of birth
- 08 is the month of birth
- 12 is the day of birth
- 1 is the checksum
Gender 1 uppercase character for the gener (F = female; M = male)
Example: F
Expiry (expire date) + checksum: 6 digits + 1 digit
Example: 2103318 with
- 21 is the year of expiry
- 03 is the month of expiry
- 31 is the day of expiry
- 8 is the checksum
Nationality: 3 uppercase character, i.e TUR for Turkey
Example: TUR
Total checksum: 1 digit
The checksum, with reference to all parts as explained above Example: 6