What record company is ac dc with?

They use several companies: Sony was used for High Voltage. Atlantic (was used for Back In Black), Elektra (you can actually write to Malcom and Angus through Elektra), UK's What Records (this is one compamy you can order the new Black Ice album from), and others of course... It depends on their budget, what they want creatively, and who is willing to work with them (or who they are willing to work with...) etc.