Promo price, connection fee, price jump: what does a tariff really cost?

Why the advertised monthly price is often not what you pay, and how to work out the real cost over the term.

All prices in this guide come from our comparison of 274 German mobile tariffs and are average prices per month over 24 months, one-time costs included. As of 18 Oct 2026.

Three tricks that push the advertised price down

• Promo price: the first months are cheaper, then the monthly fee goes up. The low price is what gets advertised.
• Connection fee and starter pack: one-time costs, often between €10 and €40, that do not show in the monthly price.
• 4-week billing: with prepaid you pay 13 times a year, not 12.

How to work out the real price

Add up everything you pay in 24 months and divide by 24:

Average price = (all monthly fees over 24 months + one-time costs) ÷ 24

Example: €5 for the first 6 months, then €15, plus a €20 connection fee. That is 6 × €5 + 18 × €15 + €20 = €320, or €13.33 a month on average, almost three times the advertised price. We show exactly this figure for every tariff as “Avg. per month” and sort by it.

The biggest gaps today

A tariff with a promo price is not automatically bad: if it is still the cheapest on average over 24 months, it is worth it. But set yourself a reminder for the end of the promo period, to switch or cancel then.

All tariffs sorted by real average price · How we calculate