Where Your AP Process Is Leaking Money — and How to Find It in a Week

Most accounts payable workflows have at least three places where dollars quietly disappear. The worst part? Many business owners have no idea it's happening until a CFO or accountant sits down and looks.

I've seen this pattern repeat across dozens of small and mid-size companies: a process that's been in place for years, nobody's questioned it, and thousands of dollars are walking out the door every month in duplicate payments, missed discounts, and processing inefficiency.

Here's how to identify yours — and what to do about it before your next close.

The Daily Check-Run Trap

The most common mistake I see: small companies cut checks daily.

Every time an invoice lands, someone writes a check. It feels responsive, it feels controlled. But it's neither. What you're actually doing is increasing your bank fees (one check run costs less than ten), multiplying your reconciliation work, and losing any ability to batch-verify payments before they hit the bank.

The fix is simple: consolidate to two or three check runs per week. Then implement positive pay with your bank — a verification process where you submit the list of checks you've created to the bank before they clear. The bank checks every check number, amount, and payee against your list. If something doesn't match, it stops. No more duplicate payments getting through because someone processed an invoice twice. No more fraudulent checks in your name.

One client I worked with cut check runs from daily to twice weekly and reduced AP processing time by 40% while eliminating duplicate-payment errors entirely.

Missing Purchase Order Controls

Here's a conversation I had at Valley Day & Night Clinic:

"Who approved this $8,000 medical supply invoice?"

Long silence.

Nobody knew. There was no paper trail. No PO number. No approval signature. Just an invoice that showed up and got paid because the vendor looked familiar.

Medical supply costs were substantial — and with no purchase order controls, there was zero visibility into who was ordering what, whether pricing was competitive, or whether the invoice matched what was actually ordered.

We implemented an inventory management system (ENVI) that created a complete chain of custody: every order started with a purchase requisition, moved to PO creation, required approval at a set threshold, tracked what was actually received against the PO, and then matched the vendor's invoice to that PO before payment.

The result? No more questions about who approved it. No more confusion that caused duplicate payments. No more invoices for items never received sitting in accounts payable.

For a small company, this doesn't require expensive software. A simple spreadsheet with a PO template, approval sign-off, and a reconciliation process does the job. The key is documenting the approval and matching invoice to PO before payment.

Invoice Matching Failures

The third leak: invoices that don't match what you ordered or what you received.

A vendor invoices you for 100 units. You only ordered 80. The invoice price is higher than the quote. You received 75 units but haven't marked it in the system yet.

Without a matching process, these inconsistencies slip through. You pay for things you didn't order. You pay incorrect quantities. You miss price overages.

A three-way match is the standard: Purchase Order (what you ordered) → Receipt (what arrived) → Invoice (what the vendor bills). Before you pay, these three documents should align on quantity, price, and description. If they don't, the invoice gets held until discrepancies are resolved.

This process caught a recurring overcharge at one client's office: a vendor was invoicing for a service retainer amount that had actually been reduced six months prior. Nobody noticed because nobody was comparing contracts to invoices. One week of focused reconciliation identified $6,000 in overcharges going back six months.

How to Find Your Leaks in a Week

Day 1-2: Pull your last three months of AP reports and your check register. Look for duplicate invoice numbers, same vendor paid twice in one week, or unusually high amounts for routine expenses.

Day 3-4: Pick your ten largest vendors. Pull their contracts or quotes. Compare the terms to what you've actually been paying. Are prices what you agreed to? Has pricing changed?

Day 5: Review your check-run frequency. Count how many times per week you're running checks and how many individual checks you're processing. Calculate what a consolidated schedule would save you.

Day 6-7: Identify whether you have purchase order controls. If not, that's your biggest opportunity. If you do, test them: pull a recent large invoice and verify there's a corresponding PO with approval documentation.

By the end of the week, you'll have a clear picture of where money is leaking. In most cases, you'll find enough to justify a conversation with your accounting team about tightening the process.

What Comes Next

Once you've identified the gaps, the fixes are straightforward: consolidate check runs, implement positive pay, create POs for all purchases above a threshold, and verify three-way matching before payment.

Most of these changes cost nothing beyond time and discipline. A few — like positive pay or an inventory system — have modest fees but pay for themselves in weeks through the errors they prevent.