Taylor Pipeline sued P.D.G. and Hypower for payment on an airport construction project, claiming conversion, negligence, and unjust enrichment. The court ruled against Taylor because Taylor had no direct contract with either defendant—Taylor's only contract was with Directional Road Boring, who was a subcontractor further down the chain. This means you cannot sue companies you didn't contract with directly, even if they benefited from your work.
Get a written contract directly with the party paying you. If you're a sub-subcontractor, you have no legal claim against general contractors or higher-tier subs you didn't contract with.
Privity of contract matters. You can only sue for payment, conversion, or unjust enrichment against parties you have a direct contractual relationship with.