No Employee will let a pay discrepancy go without a fight. Take a look at the battles employers have lost over commission payments.

* A promise is a promise: An employee was promised a 60% commission. But he later discovered that his commission checks were being calculated at a lower percentage. In court, the company argued that the employee was at-will, so it had the freedom to change his working conditions.

Court: "Even in an at-will agreement, the employer is not at liberty to change the agreed upon rate of pay after the associated work has been performed."

Avoid this trap: Do not change commission rates without first informing employees, or apply the new rate retroactively to work that has already been performed.

* Show me the money: After an employee filed a law suit under the Family and Medical Leave Act (FMLA), her employer refused to pay her commissions earned while she was on leave. The company claimed employees do not have the right to collect commissions while on FMLA leave. An appeals court disagreed, finding that an employer is liable for "any wages, salary, employment benefits, or other compensation denied or lost" to an employee due to an FMLA violation. Commissions, it said, fell under "other compensation." The court also noted that the company had previously paid earned commissions to other employees out on leave. It ordered the company to pay close to $80,000.

Avoid this trap: Know your laws and past practices. In this case, both pointed to the payment of commissions earned while the employee was out on FMLA leave.

* Commission commotion: After an employee was fired, she was denied commission on a major deal she had contributed to before her termination. The company claimed that commissions were not paid when the deal was made, but rather when the products were shipped. The employee, it pointed out, was fired prior to the products being shipped. A jury sided with the employee and awarded her $98,364. Reasons: There were evidence that determinations of who would receive commissions were made at the time of the sales agreement; even though commissions were normally paid after the company received the money from the sales, it was known to have made exceptions.

Avoid this trap: Get your policies and practices straight as to when and how commissions are determined. Put commission policies and agreements in writing. That way, you can run everything by legal counsel to ensure they’re on the up-and-up, and such documentation will also lessen the chance of confusion or mis-interpretation by employees and managers. Be sure to cover:

1. when commissions are earned;

2. when they will be paid;

3. what the percentage is based on;

4. how they will be paid;

5. what happens if the employee is fired or quits;

6. what happens if a deal ends up falling through; and

7. whether there are exceptions to the rules and what they are.