NJ has a State Law that requires final payment upon final inspection & approvals. There is NO percentage or amounts mandated; that is up to the contractors and customers within the contract terms.
I used a 'progress payment' schedule, based upon materials delivered and work completion. Most jobs were bill on 1st, check on 15th; 14 day billing to payment terms, which worked well.
Progress payments were calculated on materials & labor expended.
Large materials items (ltg pkg; gear) occasionally required a deposit.
