Will you "claw back" commissions paid for uncollectible accounts. Be sure to check with state labor laws of this is legal. Itf it can be done, your payroll folks will have to recalculate social security and unemployment taxes.
If you don't figure out how to handle bad debts what is keeping a not so honest sales rep from writing up a bunch a "fictictus" orders getting the commission money and leaving.
If you have a lot of local sales, consider a five or ten percent discount for a check with the order. Everybody wins. The client saves, the station gets it's money and the salesperson get the commission next paycheck.