All households in Germany are obliged to pay a TV and radio licence fee (Rundfunkbeitrag) of €17.50 per month for radio, television and internet services made available by public broadcasting companies. This fee is a fixed sum regardless of how many people live in the household or how many receivers are used. It is usally collected by a fee-collecting agency known as the "Gebühreneinzugszentrale" (GEZ).
Under certain circumstances, you may be eligible for a reduced fee or exempted from paying altogether.
Further information can be found here: