Deutsche Telekom and Vodafone provide free SIM cards for refugees from Ukraine. The cards are apparently mainly distributed directly on the trains to Germany. You can also get a free SIM card directly from Deutsche Telekom stores. The prerequisite is a valid Ukrainian identity document. You can use the SIM cards free of charge until June 30, 2022. They only work within Germany. Information on this can be found in German, English and Ukrainian at telekom.de.
SIM cards are not expensive. Nor do you have to sign a contract. You can find out more about mobile communications our chapter "Mobile phone contract". Important: You will need a document proving your identity in order to activate your SIM card. This can be your passport or a paper issued by a German authority.
At the moment, extensive support is offered. Free SMS and phone calls to Ukraine are currently possible with these providers, among others: Vodafone, Deutsche Telekom, Congstar, PŸUR, Sipgate, Kaufland mobil, Aldi Talk, Penny Mobil, ja!mobil, Telefónica Deutschland (o2) as well as Simfonie (Austria) and Sunrise (Switzerland). With almost all providers, data roaming in Ukraine is also free of charge.