My commission is received when customer has paid their final balance. Currently I am waiting for a commission check for two orders, however, an order was cancelled not relating to my current commission, but, my employer is withholding the check until the cancelled order is paid fully claiming the salesperson are responsible for payment for all customers. Can they do that?
Employment / Labor Attorney
It depends on the agreement between you and your employer, if any, or else on the employer's policy for paying commissions. Unless the employer has an explicit policy on this, you've got a pretty strong position.
Contracts / Agreements Lawyer
You would have to look at your employment contract. Salary / hourly wages cannot be deducted from, but if your commission can be zero if the loss on won order cancels the profit from another order.
You should contact an attorney in your area to review your employment contract and discuss all the facts.