Wage reporting when hours change weekly

I work some days through a staffing agency while still certifying. The form asks for gross earnings, which I do not see until later. Did anyone get an overpayment notice from a mistake?

Report honestly and keep your stubs. An honest small error is much easier to fix than a missing report.

Thanks for writing this out. I went through something close to it last year, and it settled down once I kept a simple log of every call and form.