I was just recently switched from Exempt to Nonexempt and I work 40 hours a week. Can an employer enforce not paying for overtime unless its"preapproved by the company first" before they have to pay time and a half according to the law?
In the US, if you are non-exempt, generally overtime must be paid at time-and-a-half for anything over 40 hours. It's illegal to not pay you at the correct rate.
But then again, it's not illegal to not offer overtime.
Read up on the Fair Labor Standard Act.
Your company has a policy that any time worked beyond 40 hours must be approved. So if you do work beyond 40 hours with out approval then you are violating that policy. If a supervisor orders you to work overtime with out management approval then they are violating that policy.
Either way your employer is required to follow the law regarding compensation. If you work 41 hours in a week they are required to pay that 1 hour at time and a half regardless of if it was approved or not.
However, If you worked that extra hour with out approval then you could be subject to disciplinary action. This is no different that if you are scheduled to work 8-5 and you decide on your own to come back it at 8pm after everyone has left and work another 4 hours. They must pay you for that time you worked, even though it was not authorized or approved. But they are probably going to some sort of disciplinary action. And it is conceivable that working unapproved and unauthorized hours could result in your termination for cause.