Operators including Orange, Deutsche Telekom and Vodafone Group agreed to reduce wholesale roaming charges with Ukrainian carriers for three months to help an estimated 4.2 million refugees keep in contact with the nation.
The companies are among a total of 27 which committed to deliver connectivity to people escaping a war in Ukraine in a movement led by the European Commission (EC) and European Parliament.
Ukrainian operators Kyivstar, Vodafone Ukraine and lifecell are among the operators involved. In a joint statement, the EC explained many refugees have fled to neighbouring countries including Poland, Slovakia, Hungary and Romania.
Bouygues Telecom, Liberty Global, Telenor, Telia and Telecom Italia are also on board, along with virtual network association MVNO Europe.
A large number of the operators had previously provided free calling to Ukraine.
The European Union (EU) regulates wholesale data roaming charges.
Operators also agreed to reduce termination rates for calls from Ukrainian numbers to the same level as those originating from EU member states.
EC VP Margrethe Vestager issued a statement urging other operators across Europe to join the initiative.