Krankenkasse requests proof of income: what to do

A letter headed Einkommensanfrage or Einkommensnachweis asks about your income. First identify the task: completing a questionnaire, providing evidence or checking a calculation.

This guide covers income requests for calculating contributions under voluntary statutory health insurance, called freiwillige Versicherung.

Why does the insurer ask about income?

Income affects these contributions. Without required evidence, the insurer may charge the maximum contribution. TK explains.

Five things to check in the letter

1. Recipient: Are the name and insurance number yours?
2. Subject: Is this about income, family insurance or a contribution already assessed?
3. Period: Which year or month does the request cover?
4. Documents: Which evidence is listed? Is there a questionnaire to complete?
5. Deadline and delivery: When must you reply, and which submission method is specified?

Write down your answers. If the letter concerns Familienversicherung, ask about the requirements for family insurance specifically.

Which documents should you prepare?

For self-employment, the Einkommensteuerbescheid, your income tax assessment, is normally used. New businesses may initially estimate income. AOK guidance.

Match document names to the request. Do not substitute a tax return for a tax assessment without checking. Make sure copies are readable and include the requested pages.

What if your tax assessment has not arrived?

Tell the insurer. hkk explicitly asks members to respond even when the latest tax assessment is not yet available. hkk guidance.

You can write in German:

Zu Ihrem Schreiben vom [Datum]: Mein aktueller Einkommensteuerbescheid liegt noch nicht vor. Welche Unterlagen kann ich vorläufig einreichen? Bitte bestätigen Sie mir die geltende Antwortfrist.

Replace [Datum] with the letter's date. This asks which documents you can provide provisionally and requests confirmation of the reply deadline. It does not automatically extend it.

Before and after sending

Use an official contact channel for your insurer. Keep your reply and proof of submission. If time is short, contact the insurer now.

If you already have a Beitragsbescheid, a contribution assessment, also check its calculation and appeal instructions. Do not treat a questionnaire reply as an appeal.

Checked: 8 September 2026. General guidance; confirm requirements for your situation with your insurer.