Formal Obligation
Visa applicants often have to submit a formal obligation at the German embassy or consulate abroad.

Formal Obligation for Foreign Visitors
If a formal obligation („Verpflichtungserklärung“) is required, the visitor's host has to make a formal pledge to cover any potential costs concerning the foreign guest. By signing a formal obligation hosts agree to the following responsibilities:

to pay all costs of subsistence for the visitor

to refund any public resources, if the visitor should need social assistance (including accommodation, medical care, nursing care)

to pay any costs for removal procedures (if the visitor should have to be sent back to the country of origin by German authorities)

Hosts have to live in Germany. Non-EU nationals need to be holders of a permanent residence permit or a temporary residence permit exceeding the validity of the formal obligation. A formal obligation may also be signed by a company residing in Germany.
To sign a formal obligation, hosts have to apply in person with the following documents:

valid passport or ID

current proof of income:
   employed workers: salary statements of the past three months, pensioners: pension statement, freelance and self-employed workers: current tax certificate, tax consultant's statement of your net profit after tax covering the previous three months (if this statement is made without a professional tax consultant it requires your personal signature)

personal data of your visitor:
   surname and first name
   date and place of birth
   nationality
   address (in country of origin)
   passport number (or copy of passport)

Fee
  29 euros
Please note:
visa applicants need proof of a travel health insurance for Germany (provided by visitor or host)
hosts have to send the formal obligation (in original) to their visitor, who has to submit the document at the German embassy or consulate
the formal obligation should not be older than six months when the visa application is submitted
hosts must apply in person for a formal obligation and cannot engage or authorize a third person to act in their name
the German representation abroad is the competent authority for the visa procedure. Please contact the embassy or consulate for any questions regarding the visa application.