The first action would be to question "why". All of our jobs are based on estimated costs, and if the actual cost of material, freight or installation exceeds our budget, our profit and margins become lower.

If a warning is issued, my first step would be to insure the invoice is being applied to the correct job. Identifying mistakes like this BEFORE entering would be so much less time consuming than recognizing them after the invoice is posted.
Second step could be contacting the vendor to check the cost.
Several other things come to mind before saying okay, sales staff made an error and we have to "eat it".

It would be very useful for us, and thanks for takinig the time to question my reasons.

Karen