If an employee was paid holdiay pay, but it should have been overtime pay, howcan this be corrected when it's too late to void the check?

If it's OK with the employee, do it on the next paycheck:

On the check, use the holiday pay item and put negative hours next to it to back out that pay.

Then add another line to the earnings table for the overtime pay with positive hours.

Good afternoon, @diane49.

Welcome to Community. Thanks for joining us. 

At this time, you'd need to contact support as this was a prior quarter, and the pay period is locked, which would cause you not to edit it. By contacting support, they could unlock the file to allow the edit. 

To contact support: 

1. Open QuickBooks.
2. Go to Help, then select QuickBooks Desktop Help.
3. Select Contact Us.

If you have further questions or concerns, feel free to reach back out. I'm always happy to lend a helping hand. Take care!

@Tori B 

RE: At this time, you'd need to contact support as this was a prior quarter, and the pay period is locked, which would cause you not to edit it

What?  There is no need to contact support for this. It can be fixed with a new off-cycle paycheck, or on the next regular paycheck.

In any case, given that holiday pay and overtime use two different rates of pay, there is no way to effectively change a past check that has been issued and cashed - or direct deposited.  It's water under the bridge.

Why push the customer to down a path that is not useful?