An owner on a private commercial construction job is paying cash for the project, and doesn't want to complete the "credit app" information. I know there is limit on residential projects of $1000, or 10% of the contract amount, whichever is Lower, but I have not been able to find a source identifying any commercial limits.
There's no limit on the size of a down payment for commercial jobs. You can ask for however much you want as a down payment. The only limit is on residential remodel jobs.
I don't believe there is a limit on a commercial project.