German households can buy electricity or gas from the local default supplier, or they can sign a contract with another supplier. For the second kind, the Energy Industry Act sets a form. Section 41b says: Energielieferverträge mit Haushaltskunden außerhalb der Grundversorgung und deren Kündigung durch den Energielieferanten bedürfen der Textform. Energy supply contracts with household customers outside the default supply, and their cancellation by the supplier, require text form. The contract must exist as a readable text that can be stored, such as a letter or an e-mail. A yes spoken on the phone does not meet this requirement. The same section also obliges the supplier to confirm a customer’s cancellation in text form within one week.