What Is an Open Invoice?
An open invoice is an invoice that has been issued but not yet paid in full, so a balance is still owed on it until payments or credits bring it to zero. The seller carries it in accounts receivable, the money customers owe, and the buyer carries it in accounts payable, the money owed to vendors.
When a landscaping company bills a property manager $4,850 for fall cleanup on September 2 with 30 days to pay, the invoice stays open until it's paid in full, early, late or in pieces, though each side's books may open and close it days apart.
What "open" means on an invoice
Open describes the balance, not the calendar. An invoice is open the day it goes out, even if the payment terms give the buyer a month. Payment terms are the deadline printed on the invoice, such as "net 30," which means the full amount is due 30 days after the invoice date.
So open and overdue are different things. Every overdue invoice is open, but many open invoices aren't due yet. Accounting software usually shows a status next to each one:
| Status | What it means | On a $4,850 invoice due October 2 |
|---|---|---|
| Open, not yet due | Balance owed, due date still ahead | September 15, nothing paid |
| Partially paid | Some money received, the rest still open | $3,000 paid, $1,850 open |
| Overdue (past due) | Still open after the due date | October 10, $1,850 unpaid |
| Paid (closed) | Balance is zero | Final $1,850 received |
| Void | Cancelled, nothing was ever owed | Sent to the wrong customer |
How an open invoice gets closed
Most invoices close when the buyer pays in full. The other routes cause the confusion:
- The buyer pays in pieces, and the invoice closes when the last payment lands.
- Goods come back or the price was wrong, so the seller issues a credit memo that cuts the balance, and the buyer applies it to the bill.
- The seller gives up on collecting and writes the balance off.
- The invoice should never have gone out, so the seller voids it.
Only the seller can close an invoice by crediting, writing off or voiding it. Say a buyer deducts $300 for a damaged delivery and pays the rest. The bill looks settled in the buyer's books, but the seller still shows $300 open until it agrees and sends a credit. Paying less than the invoice like this is a short payment, and it leaves the two sets of books out of step.
Worked example: one invoice on two sets of books
The landscaping company emails invoice 1027 for $4,850 on September 2, terms net 30, so it's due October 2. The property manager pays for two of the three properties on September 25 and holds the rest until it can walk the third site. ACH, used below, is an electronic bank-to-bank transfer.
| Date | What happened | Open on the landscaper's books | Open on the property manager's books |
|---|---|---|---|
| Sep 2 | Invoice 1027 sent by email | $4,850 | $0 (not entered yet) |
| Sep 4 | Property manager enters the bill | $4,850 | $4,850 |
| Sep 25 | Property manager sends $3,000 by ACH | $4,850 | $1,850 |
| Sep 29 | The $3,000 reaches the landscaper's bank | $1,850 | $1,850 |
| Oct 2 | Due date passes | $1,850, now overdue | $1,850, now overdue |
| Oct 14 | Property manager mails a check for $1,850 | $1,850 | $0 |
| Oct 20 | Landscaper deposits the check | $0 | $0 |
Behind each row are ordinary journal entries, where every amount is recorded once as a debit and once as a matching credit. When the invoice goes out, the landscaper debits accounts receivable $4,850 and credits landscaping revenue $4,850. Each payment it receives is a debit to cash and a credit to accounts receivable, $3,000 and then $1,850.
The property manager does the mirror image. It debits grounds maintenance expense $4,850 and credits accounts payable $4,850 when it enters the bill, then debits accounts payable and credits cash for each payment. The two payments add up to $4,850, so both balances end at zero.
On three of the seven dates the two columns disagree, only because a document or a payment was still in transit. That's normal, and it's why the monthly statement of account a vendor sends often doesn't match your books to the penny. On September 30, both agree: $1,850 is open.
Open invoices and your taxes
Whether an open invoice counts toward this year's income or expenses depends on your accounting method, as IRS Publication 538 explains. Under the cash method, you generally report income in the year you receive it and deduct expenses in the year you pay them. Under an accrual method, you generally report income in the year you earn it, regardless of when payment arrives.
For the seller, that means open invoices can be taxable before they're collected. An accrual-basis contractor with $60,000 of open invoices on December 31 has already counted that $60,000 as income for the year. A cash-basis contractor counts it next year, when the checks come in.
The buyer's side has more conditions. An accrual business generally deducts an expense once two tests are met: the all-events test, meaning the liability is fixed and the amount can be worked out with reasonable accuracy, and economic performance, which for goods and services you buy means they've been provided. Some recurring expenses get an exception. A cash business deducts the bill when it pays. Your CPA can confirm how this applies to a big open bill at year-end.
When an open invoice won't close
For a seller, an invoice that stays open past its due date gets a reminder, then a call, then a hold on new work. Once it's clear the customer won't pay, you write it off. The IRS rules on business bad debts allow a deduction only if the amount was included in your gross income in the current or a prior year. In practice, an accrual-basis seller can usually deduct an uncollectible invoice and a cash-basis seller can't, because it never counted that money as income.
You deduct a debt in the year it becomes worthless. If only part of it is uncollectible, you can deduct only the part you write off in your books that year. You also need to show you took reasonable steps to collect, though you don't have to sue if a court judgment would be uncollectible.
Federal work has its own rules. Under the Prompt Payment Act, when a contract with a federal agency sets no due date, payment is generally due 30 days after the agency receives a proper invoice. If the invoice arrives within a week of delivery, the 30 days generally count from the seventh day after delivery instead. Some foods, such as meat and dairy, have shorter deadlines.
On federal construction contracts, progress payments are generally due 14 days after the agency receives a proper payment request. These deadlines cover what an agency pays its own contractor. Subs fall under a separate clause: the general contractor must pay them for satisfactory work within 7 days of being paid by the agency.
An agency that pays late adds interest automatically, at a rate the Bureau of the Fiscal Service set at 4.75% for July 1 to December 31, 2026. With private customers, late fees and interest depend on your contract and your state's law.
Keeping track of open invoices
A weekly look at open bills is enough for most small businesses: what's due in the next seven days, what's on hold and why, what's late. An AP aging report groups those open bills by how many days past due they are, so the old ones stand out. Bills stuck waiting for a signature usually mean a gap in your invoice approval workflow, the steps between a bill arriving and a payment going out.
On the payables side, the hardest open invoice to manage is the one nobody has entered yet. With Clyr's bill pay and accounts payable tools, vendors email invoices straight in and the line items are extracted automatically, so a bill joins the open list the day it arrives. Approvals route by your rules, you pay by ACH or mailed check, and Clyr syncs two ways with QuickBooks, Xero, Sage Intacct and NetSuite.
FAQs
Yes. If the customer's check bounces, an ACH payment is returned or a card payment is reversed, the seller reverses the payment in its books and the invoice reopens. The same happens when a payment was applied to the wrong invoice: fixing it reopens one invoice and closes another. As the buyer, expect a fresh past-due notice, and possibly a returned-payment fee if the vendor's terms include one.
Until it's paid, credited, voided or written off. Nothing in accounting closes an invoice just because it's old. Age is still a warning sign. For the seller, the odds of collecting fall the longer an invoice sits. For the buyer, a bill months past due usually means a dispute nobody wrote down or an approval nobody gave. Pick a cutoff, such as 90 days past due, to decide each one.
An open purchase order is a commitment: you've approved buying something, but the goods, or the bill for them, haven't fully arrived. An open invoice is a debt the vendor has already billed. Take a $10,000 purchase order for lumber with $6,000 delivered and invoiced. $4,000 is still open on the purchase order, and until you pay, $6,000 sits in open invoices. Cash forecasts need both numbers.
Some online stores and payment providers use "open invoice" for a pay-later option: the shopper gets the goods with an invoice and pays it within a set number of days instead of at checkout. If your business buys supplies this way, record the purchase as an unpaid bill until you pay it.
Only when it's worth something to you, usually because of an early payment discount. Terms of 2/10 net 30 mean 2% off if you pay within 10 days, otherwise the full amount in 30. On a $5,000 bill, that's $100 for paying 20 days early. Without a discount, paying on the due date keeps the cash in your account longer.
