Goodday

Could anyone suggest what I could check. I have a problem with POS daily cash up variances. They seem to be happening regularly with some days reflecting shortages in cash and other times reflecting overs in cash.
I have checked the sales journal to the invoices printed from the POS and all seems fine. I checked the integrity of the data all seems fine so I am quite flumaxed what could be causing these variances.

Many thanks
Lin