The marketplace itself does not contain or enforce any special requirements for business sellers. Nevertheless, and according to the German Consumer Rights Directive from 13.06.2014, some essential obligations apply for all online sellers (businesses, not private people) no matter where they are located:
Right of withdrawal
Merchants must give consumers a minimum of two weeks cancellation period. They also must instruct consumers about their rights and provide a withdrawal form. Merchants are now no longer required to pay for return shipping for orders costing 40 Euros or more. They are free to decide whether they or the customer should pay for the return.
If the customer files a complaint about product defects in the first six months, the merchant has to prove the defects didn’t already exist at the time of purchase. After the first six months, however, the customer has to prove the defects were already there to ask for a refund.
A major point is the now regulated information obligations for online retailers. Whether it's transparent delivery conditions, information about statutory warranty rights, or pointing out warranty conditions - retailers have to consider a whole range of obligations. You can ask the “Händlerbund” for support.
To correctly define your business’ terms and conditions, Circles recommends consulting a lawyer and not using the terms and conditions templates.