The wage tax deduction is usually carried out for you by your employer on the basis of the electronic wage tax deduction characteristics (ELStAM). In some cases, however, it is not possible to retrieve the ELStAM, e.g. because

• Reporting data is incorrect,
• Your employer does not participate in the ELStAM procedure,
• you have not (yet) been assigned an identification number, even though you have unlimited tax liability and are required to register in Germany,
• you belong to a group of people who cannot yet participate in the ELStAM procedure because they are not required to register in Germany:
  • Employees with unlimited tax liability who do not have a place of residence (e.g. homeless persons, detainees).
  • Employees with limited tax liability as defined in Section 1 (4) EStG who apply for an allowance in the wage tax reduction procedure
  • Employees with extended unlimited tax liability within the meaning of § 1 (2) EStG
  • Employees to be treated as employees with unlimited tax liability within the meaning of Sec. 1 (3) EStG upon application

Upon request, the responsible tax office will then issue you with a "certificate for the deduction of income tax", which can be used as a substitute by your employer as a basis for the deduction of income tax (so-called substitute certificate). If your employer does not have such a certificate, he must deduct the wage tax according to tax class VI.