Under normal arrangements and unless a sub-contractor has a self-billing arrangement process, he will supply an invoice to his contractor once the works for which he has been engaged have been completed to the required standard.  He will then be paid in accordance with the terms of his contract, and if a specific job takes a number of weeks the payment might be under a “draw-down” arrangement. He might also be paid under a “day rate” arrangement where the sub-contractor is paid in arrears, which is generally weekly, but might also be fortnightly or monthly.