Accounts payable and accounts receivable are the two ledgers that track money owed on credit: accounts payable (A/P) is what your business owes suppliers for goods or services bought on credit, and accounts receivable (A/R) is what customers owe your business for goods or services you delivered on credit. A/P sits under current liabilities on the balance sheet; A/R sits under current assets. The gap between when cash comes in through A/R and when it goes out through A/P is what determines whether a business can pay its bills on any given week.
How Accounts Payable Works
Every time your business buys something on credit, the amount owed is recorded as A/P. Most invoices carry terms between 30 and 90 days, depending on what you negotiated with each supplier.
The lifecycle starts when goods or services arrive and the supplier sends an invoice. Before anyone cuts a check, a well-run A/P process performs a three-way match: the invoice is compared against the original purchase order and the receiving report to confirm the quantities, prices, and items line up. If something doesn’t match, payment is held until the discrepancy is resolved. Skipping this step is how businesses end up paying for inventory they never received or at prices they never agreed to.
Suppliers often offer early payment discounts. A common one is “2/10 Net 30,” meaning you get 2% off if you pay within 10 days; otherwise, the full balance is due in 30 days. Two percent sounds small, but on an annualized basis, skipping the discount to hold cash for the extra 20 days costs you roughly 36.7%. Taking the discount usually beats any return you’d earn leaving that cash in the bank.
When no discount is on the table, the opposite move applies: hold cash until the due date. Paying on day 29 of a Net 30 invoice instead of day 5 gives you almost a month of interest-free financing. The trick is not crossing into late territory, because late payments damage supplier relationships and can lead to worse credit terms later.
Choosing How to Pay
Payment method affects both cost and timing. ACH transfers are free or nearly free and clear in one to a few business days, with same-day ACH available at some banks. Wire transfers land the same day but typically cost $10 to $35 domestically and more internationally. ACH handles most routine A/P. Wires make sense when speed matters or when paying overseas suppliers where ACH isn’t available.
How Accounts Receivable Works
A/R is the flip side. When you deliver goods or services and send an invoice with credit terms like Net 30 or Net 60, the unpaid balance becomes A/R. It’s a current asset because you expect to convert it to cash within the normal operating cycle.
A/R only has value if you actually collect it. The biggest risk is bad debt, where a customer never pays. Any business extending credit needs a realistic estimate of how much of its receivables will go uncollected. Accountants call this the allowance for doubtful accounts, and it reduces the reported A/R balance to what the company realistically expects to receive. Common ways to calculate it: applying a flat percentage based on historical write-off rates, using the aging report to assign higher default rates to older invoices, or evaluating individual customers based on payment history.
Reading an Aging Report
The aging report is the most practical tool for managing A/R. It sorts every unpaid invoice into buckets by how long it has been outstanding, usually in 30-day increments: 0–30 days (current), 31–60 days, 61–90 days, and 90-plus days. The further an invoice drifts to the right, the less likely you are to collect it. An invoice at 90-plus days isn’t just a financial concern; it’s a signal that your collection process has a hole in it.
A clear, consistently enforced credit policy is the first defense. Payment deadlines, late fees, and the point at which you escalate to formal collection should all be spelled out before you extend credit. Following up early and often on overdue invoices works far better than waiting and sending an aggressive letter at 90 days. Most businesses that struggle with cash flow aren’t failing to make sales. They’re failing to collect on them.
How A/P and A/R Connect
Every credit transaction creates both an A/P and an A/R. When you buy supplies on credit, the amount shows up as A/P on your books and A/R on your supplier’s books. Same dollar amount, recorded by two different companies from opposite perspectives. That mirror relationship means every slow-paying customer on your aging report is causing the same cash flow headache for you that you’d cause your own suppliers if you paid late.
The practical tension is timing. You need cash coming in from A/R fast enough to cover what’s going out through A/P. When a major customer pays 15 days late, that delay cascades: you miss a supplier’s early payment discount, or worse, you pay late yourself and damage a relationship you depend on. Managing A/P and A/R in isolation is a mistake. They’re two halves of the same cash flow equation.
Measuring the Gap: DSO, DPO, and the Cash Conversion Cycle
Two numbers tell you how efficiently your A/P and A/R processes are running. Days Sales Outstanding (DSO) measures how many days, on average, it takes to collect payment after a sale. Divide total A/R by total credit sales for the period, then multiply by the number of days in that period. A lower DSO means you’re converting sales to cash faster.
Days Payable Outstanding (DPO) measures the other side: how many days, on average, your business takes to pay its own suppliers. A higher DPO means you’re holding cash longer before it goes out. The goal is a low DSO paired with a relatively high DPO, though pushing DPO too high risks the supplier damage described above.
These two metrics feed the cash conversion cycle (CCC): Days Inventory Outstanding + DSO − DPO. Days Inventory Outstanding measures how long inventory sits before it sells. A shorter CCC means your business moves from spending cash on inventory to collecting cash from customers in fewer days. A negative CCC, where DPO exceeds the sum of inventory and collection days, means suppliers are essentially financing your operations. Some large retailers operate this way, but it takes significant leverage over suppliers.
Turning Receivables Into Cash Faster
When the gap between collecting A/R and paying A/P gets too tight, businesses sometimes sell their receivables to a third party, a practice called factoring. A factoring company buys your unpaid invoices at a discount and takes over collection. You typically receive 70% to 90% of the invoice value upfront, with the factoring company paying you the remainder, minus their fee, after collecting from your customer.
Factoring fees generally start between 0.7% and 2% of the invoice value for a 30-day period, with volume discounts for businesses that factor regularly. The key difference from a loan is that factoring doesn’t create debt on your balance sheet. You’re selling an asset, not borrowing against it. The tradeoff is cost: factoring runs more expensive than a traditional line of credit, but it’s available to businesses that might not qualify for bank financing because approval depends on your customers’ creditworthiness, not yours.
When Formal A/P and A/R Tracking Is Required
Not every business needs to maintain formal A/P and A/R ledgers. Under the cash method of accounting, you record revenue when you receive payment and expenses when you pay them, with no formal tracking of what’s owed in either direction. The accrual method records revenue when earned and expenses when incurred, regardless of when cash changes hands. A/P and A/R exist because accrual accounting requires you to track these credit obligations.
Federal tax law determines which businesses must use accrual. C corporations, partnerships that include a C corporation as a partner, and tax shelters are generally required to use it. Any of these entities is exempt if its average annual gross receipts over the prior three tax years fall below a threshold set at $25 million and adjusted annually for inflation.1Office of the Law Revision Counsel. 26 USC 448 – Limitation on Use of Cash Method of Accounting Farming businesses and qualified personal service corporations (fields like law, accounting, engineering, and consulting) are also exempt regardless of size.2Internal Revenue Service. Publication 538, Accounting Periods and Methods Sole proprietors and most small partnerships can use either method. In practice, the smallest businesses often skip formal A/P and A/R entirely, while any business approaching the gross receipts threshold should prepare to switch to accrual and the record-keeping it demands.
1099 Reporting Tied to A/P Records
Managing A/P isn’t just about paying bills on time. Payments to independent contractors and other non-employees trigger federal reporting. For tax years beginning after 2025, businesses must file Form 1099-NEC for any individual or unincorporated entity paid $2,000 or more during the year for services. The threshold was previously $600 and will adjust for inflation starting in 2027.3Internal Revenue Service. General Instructions for Certain Information Returns (2026) Missing these filings can result in penalties that scale with how late you file, so your A/P records need to track not just what you paid and when, but who you paid and whether they’re an employee or a contractor. Businesses that don’t keep clean A/P records often discover the reporting gap at tax time, when reconstructing a year of payments is far more painful than tracking them as they happen.