It’s almost never the quality of the work. It’s the file. Rejections cluster into a small number of causes, and nearly every one can be prevented:
- A mismatch. The invoice says something the PO doesn’t: a different rate, service name, quantity or period.
- Missing proof. No sign-in sheet, delivery confirmation or signature behind the claim.
- A document that has to come from someone else, like a sign-in sheet the school uploads.
- No authorization. The work was done without a PO or work order covering it. That needs a conversation with whoever requested the work, not a resubmit.
- Math. Lines that don’t add up, or billing that overlaps an earlier invoice.
- Small formatting errors. A dash in the invoice number, a missing field, a name spelled two ways.
- Setup. An out-of-date vendor record or banking details.
PolarFixed AI checks for these before you submit. If one already came back, see how to fix a rejected invoice.