Telekom's Festnetz-to-Mobilfunk Switch: What Customers Need to Know to Avoid Higher Bills
This guide explains Telekom's phase-out of plain telephone lines, the cost of the offered adapter box, and the cheaper alternatives that can save customers more than 200 euros per year.
The End of the Classic Landline
The Deutsche Telekom is gradually migrating its last 1.3 million pure telephone connections – those without an internet component – to the mobile network. New standalone telephone lines have not been available for some time. The process affects customers who still use a traditional landline phone plugged directly into the wall jack.
How the Adapter Box Works and What It Costs
For customers who want to keep their existing phone equipment and number, Telekom offers a device called "Call Connect via Funk". This box sits between the telephone and the mobile network. The user plugs their old phone into the box, which then routes all calls over the mobile network.
The pricing starts at 22.95 euros per month for a tariff that includes 120 free minutes. An unlimited landline flat rate costs 32.45 euros per month. On top of the monthly fee, the box itself carries an upfront charge of 100 euros or a rental fee of 3.95 euros per month. This means a customer choosing the cheapest option with the purchased box faces an initial outlay of 100 euros and then nearly 23 euros every month.
Cheaper Alternatives Exist
Comparison portal Verivox has examined the Telekom offer and concluded it is not competitive. According to reports from dpa published across t-online, Bild, and CHIP, Verivox notes that mobile tariffs from other providers (using the Vodafone or Telefónica networks) cost as little as 5 euros per month for an all-network flat rate. Even customers who prefer to stay on Telekom's network can more than halve their monthly bill by selecting a standard Telekom mobile tariff rather than the adapter-box plan.
The difference is substantial. Switching from the Telekom adapter to an alternative 5-euro tariff saves more than 200 euros per year, and when the cost of the box is included, the yearly saving can exceed 260 euros, according to the calculations cited by Bild.
What to Look for in a New Phone
Customers who accept a new mobile number have the widest choice. A basic smartphone or a simple button phone can be bought for around 25 euros. For those who prefer the look and feel of a desk phone, dedicated mobile desk phones that work with a SIM card are available from about 70 euros – still cheaper than Telekom's box.
When buying any new device, buyers must ensure it supports 4G (LTE) or 5G. Support for only 2G or 3G is not future-proof: 3G has already been switched off in Germany, and the shutdown of 2G is scheduled for 2028. A phone that relies solely on these older standards will soon become unusable.
The transition from fixed to mobile telephony is not unique to Telekom. Other major providers like Vodafone, O2, and 1&1 have already stopped offering pure voice landlines. The change marks the practical end of the traditional wired telephone for millions of German households. The key for customers is to compare offers and avoid automatically accepting Telekom's bundled solution, which carries a heavy premium.