Sources, review rules and updates
From official data to the provider's product information sheet: which sources Internet-Guenstiger uses and how statements are checked and kept up to date.
We prefer primary sources: public authorities, legislation, product information sheets, consumer organisations and information directly from providers. We use secondary sources when they make their method and data basis clear. Our local pages also draw on announcements from municipalities, districts and network operators, on local newspapers and, as a supplement, on secondary sources such as Wikipedia or directories. Every source is linked on the page concerned, and we flag information taken from press reports in the text.
Our hierarchy of sources
Wherever possible, legal and regulatory statements are checked against official bodies. For practical guidance, we also draw on consumer organisations. We treat a provider’s marketing claims as provider information, not as independent evidence.
- Public authorities and original legal texts
- Consumer organisations
- Product information sheets and contract documents
- Methodologically transparent specialist sources
Corrections
Tariffs, rules and technology change. We check reports of factual errors and correct them in a traceable way. The update date on a page shows when it was last reviewed editorially.
Selected sources
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Methodology
How Internet-Guenstiger keeps editorial guidance, its own calculators and paid partner comparisons apart – and how our recommendations come about in a way you can follow.
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Read moreAbout us
Who is behind Internet-Guenstiger: Tim and Max Jungeblut, the founders of the Guenstiger portals, and the editorial approach behind them.
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