His work phone is cut off when he’s laid off and he smashes it on the ground outside of the firm. Paul Bettany’s character thinks he knows where he is after Zachary Quinto’s character suggests that he’s probably drowning his sorrows. When they go there, they don’t find him. While he may have had a company card, that was likely frozen, but even if he does, it seems he’d know better than to use it for unauthorized expenses. Paul Bettany’s character gets lucky and runs into him as he’s returning home at dawn (Carmello pulls up a few minutes later).
I wasn’t thinking so much about current charges on his card, and using the phone directly to find it, but rather to previous phone calls, and previous (authorized) charges, which might reveal who he often calls, and where he often goes. At any rate, seems like the most obvious answer is correct - he went home.