Am I entitled to overtime pay for after shift work duties?
If you work past the end of a shift, performing any kind of business-related duty, you are entitled to be paid for that time. In fact, your employer is legally required to pay you for it. For this reason, many employers will forbid you to work when you're off the clock. Even something as simple as helping a customer on your way out of the building can, theoretically, get your employer in trouble if you are not paid for the time.
If you find yourself performing work duties off the clock that last more than just a minute or two, you and your employer need to take steps to ensure that this either stops happening or that your paycheck is changed to reflect this work time. If your employer is requesting that you continue working or that you complete an additional task and may be unaware that you are no longer on the clock, explaining that you already clocked out. Tell your boss you'll get your time card and have him initial for the extra time as soon as you finish whatever it is he requested.
If your employer refuses to sign your time card, you may be able to file a formal complaint. Try speaking to your employer first, and if she does not stop making the requests, you may want to consider filing a claim or complaint with your state or federal Department of Labor. Further, if the amount of work you are doing after standard work hours results in you working over forty hours per week, you may also be entitled to overtime pay based on this extended time worked. If you believe you are entitled to these wages and that they have not been paid, you should strongly consider speaking with a lawyer. You may be entitled to back pay and other damages for your wage and hour claim, and your attorney can help you take the proper steps to file a claim with the labor board.