Bookkeeping Tips • November 2, 2026 • by Zachariah Smiley
Duplicate bills sneak in quietly. A vendor invoice arrives by email and gets entered, then the reminder — or the paper copy in the mail — gets entered again a week later. Both look legitimate, both sit in your payables, and if you pay both, you're the one who has to notice and chase the refund.
The check takes two minutes. Before paying, open the vendor in QuickBooks Online, sort their transactions by amount, and look for twins — same amount, same invoice number, close dates. Found a true duplicate? Void the copy rather than deleting it, so your audit trail stays clean and your reconciliation still ties out.
I find duplicates hiding in plain sight in almost every cleanup I take on here in Wichita — sometimes months old, sometimes already paid. A quick look before every payment run is the cheapest insurance in bookkeeping: it keeps your expenses honest and your cash where it belongs.
This is exactly the kind of thing I clean up and keep clean for Wichita small businesses — catch-up projects and monthly bookkeeping, quoted flat after a free look at your books.