GATX is the Entity in Charge of Maintenance (ECM) for all wagons of that GATX is either the holder and/or the owner and has received an ECM Certificate, available on ERA website ERA ECM Certificates.
With the revision of the Directive on Railway Safety in Europe, the EU introduced the term "Entity in Charge of Maintenance" in 2008. This "Entity in Charge of Maintenance" must ensure that all wagons assigned to it in the national vehicle registers are serviced in accordance with the regulations in force.