Data from a study commissioned by energy company Octopus Energy and conducted by RWTH Aachen show that loyal customers in Germany’s electricity market are being systematically disadvantaged. According to the report, providers lure households with low introductory tariffs, only to raise the price in the second year of the contract by an average of 47 % or 13 cents per kilowatt‑hour. In 2025 alone, loyal consumers paid about 11 billion euros more. Octopus Energy calls this a “loyalty penalty”.
The study was the first to quantify the gap between new‑customer offers and the rates retained for existing customers. RWTH Aachen analysed thousands of price‑adjustment letters sent to private electricity customers. Its findings indicate that as many as 30 million households-nearly three‑quarters of all German households-were hit by higher rates for existing customers in 2025, meaning they paid too much for their electricity.
Octopus Energy accuses other suppliers of a systematic “lure‑and‑rip-off” strategy. “The study shows that new‑customer prices closely track market developments” the company says. “Existing‑customer prices rise almost independently”. The adjustments are often justified generically in terms of “procurement and sales”.
Since the energy crisis, the gap between tariffs has not narrowed but widened. The study finds that the average savings for a household that switched providers between 2018 and 2021 was between €121 and €241. Today, the cost advantage of a new‑customer contract can reach up to €492 per year.