Bookkeeping & payrollAccounts Payable for Small Business: Paying Bills Without Paying Them Twice

A vendor once emailed an invoice, then mailed the same invoice, then sent a friendly "just following up" with the invoice attached a third time. All three were paid. The vendor was very nice about refunding it. It still took six weeks and two phone calls.

That's a made-up vendor, but if you've run a business for more than a year, you probably winced a little. The usual culprit for a double payment is bills arriving through four doors (email, mail, the vendor portal, a text to your operations manager) with nobody standing at any of them.

The fix is a boring, dependable accounts payable process for small business, and boring is the goal here. Below is the version we'd set up for a company that pays somewhere between 20 and 200 bills a month.

What is accounts payable, in plain terms?

Accounts payable (A/P) is the money you owe vendors for things you've already received but haven't paid for yet. On your balance sheet it's a liability. In your bookkeeping software it's a list of open bills.

The reason to track bills as A/P, instead of only recording expenses when the money leaves the bank, is timing. If your March materials bill gets paid in April, entering it as a bill in March puts the expense in March, where it belongs. That's accrual accounting (recording expenses when you incur them, not when cash moves), and it's what makes a monthly profit and loss statement worth reading.

The four-step AP process

1. Capture. Every bill goes to one inbox, like bills@yourcompany.com. Vendors get told once, nicely, and your team forwards anything that wanders in elsewhere. If you use a bill pay tool, that inbox feeds it directly.
2. Approve. The person who ordered the work confirms the bill is real and the amount is right. For a materials order, that means checking it against what actually arrived.
3. Pay. Bills get paid on a schedule, once or twice a week, on their due date or close to it. Not the minute they arrive, and not whenever someone remembers.
4. Record. The payment is applied to the original bill in your books, so the bill closes and drops off the open list.

That last step is where most duplicates are born. If someone pays a vendor by writing a check or using the debit card, and the bookkeeper later sees that withdrawal and books it as a new expense, the original bill stays open. Next week, someone sees the open bill and pays it. Again.

A worked example: the bill that got paid twice

Here is a made-up case. You run a small commercial cleaning company. On June 3, a supply vendor emails a $2,480 invoice. Your office manager enters it as a bill. On June 10, the owner, standing at the vendor's counter, pays the same invoice with the company card.

In the books, June now shows:

• A $2,480 open bill to the supply vendor (still unpaid, as far as the system knows)
• A $2,480 card charge categorized to "Cleaning Supplies"

Supplies expense is double counted at $4,960. Your gross margin for June looks worse than it was. And on June 17, the scheduled bill run pays the open bill, so now you've actually paid $4,960 in cash.

The catch would have been simple: when the card charge came through, match it to the open bill instead of creating a new expense. In QuickBooks Online, that means recording the card charge as a payment against the bill (or matching it in the bank feed) rather than adding it as a fresh expense.

The bill pay workflow reports worth checking weekly

You don't need a lot of reports. Two will do most of the work:

• The A/P aging summary. It shows what you owe by vendor and how old each bill is. Anything over 60 days deserves a look. Either it's genuinely late, or it was paid some other way and never matched.
• The unpaid bills list, sorted by vendor. Two bills from the same vendor for the same amount a few days apart is the classic duplicate pattern.

A third habit helps: when a vendor statement arrives, compare it to your open bills for that vendor. Vendors are surprisingly happy to tell you what they think you owe.

Controls that protect the bank account

AP is where a lot of small-business fraud starts, usually through a fake invoice or an email asking you to "update our bank details." Two habits handle most of the risk:

• Separate the jobs. The person who enters bills shouldn't be the only person who approves and releases payments. In a five-person company that might just mean the owner approves the weekly payment batch.
• Verify bank changes by phone. Call the vendor at a number you already have on file, not one in the email.

We go further on this in internal controls for small business that aren't paranoid, including setups for teams too small for a full separation of duties.

Where AP software fits

Bill pay tools can capture invoices, route approvals and sync to your accounting software. They help, but they don't decide who approves what or how often you pay. Set up the AP process on paper first, then pick the tool that fits it. Our map of the small business accounting tech stack shows how bill pay, the bank feed and the general ledger connect.

And AP has a mirror image: everything above, but for money other people owe you. If that side is also messy, read accounts receivable follow-up without becoming the villain.