What the Market Transparency Unit is
The Market Transparency Unit for Fuels (Markttransparenzstelle für Kraftstoffe, MTS-K) is a department of the Federal Cartel Office (Bundeskartellamt), Germany’s competition authority. It was set up after the office’s 2011 sector inquiry found too little competition in the fuel market. The legal basis is section 47k of the Act against Restraints of Competition (Gesetz gegen Wettbewerbsbeschränkungen, GWB) together with the Fuel Market Transparency Ordinance (MTS-Kraftstoff-Verordnung). After a test phase from September 2013, regular operation has run since 1 December 2013.
Who has to report what
Anyone who operates a public petrol station or decides its prices – often the oil company – must report every price change for Super E5, Super E10 and diesel within five minutes electronically. Around 15,000 petrol stations across Germany are covered. Very small stations can be exempted from the reporting duty; they are then missing from all price apps. Other grades such as Super Plus, LPG (autogas) or electricity are not covered by the reporting duty.
Since 1 April 2026 the 12 noon rule has also applied: petrol stations may only raise their prices once a day, at 12 noon, but may lower them at any time. Because every change is reported, the Federal Cartel Office can check whether everyone complies. What the rule means for when you fill up is explained in the guide The best time to fill up.
How the prices reach you
The MTS-K does not run an app or a price-comparison website of its own. It passes the data on to approved consumer information services (Verbraucher-Informationsdienste) – there were 45 of them in mid-2025. One of them is Tankerkönig.de, which makes the data available under the free CC BY 4.0 licence. Spritfuchs24.de also gets its prices from there.
Spritfuchs24.de retrieves the prices when you open a city page and shows them unchanged with the station’s name, brand and address – without hiding or favouring any station. Next to the list you can see when the prices were retrieved. Prices older than five minutes are labelled with their age; we do not show anything older than 15 minutes at all. You can find more about our method on About Spritfuchs24.de.
What else happens to the data
The Federal Cartel Office analyses the reports itself and regularly publishes reports – for example on how much prices fluctuate over the course of the day or how much of a tax cut reaches the pump. An example is in the guide Price differences. The price curves on our city pages are also based on this data; they are our own calculations from the historical data of Tankerkönig.de.
Wrong price? How to report it
If a price in the list does not match the pump, tap the warning triangle “Report an error” next to the station and enter the correct price. The report goes via Tankerkönig to the Market Transparency Unit and from there to the operator. For anything else you can reach our complaints office by e-mail; the address is in the legal notice (Impressum). The price at the pump is always what counts.
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