Why your gross margin changes when your affiliate invoice arrives

An e-commerce brand we work with ran a 10 percent affiliate commission program across four platforms. Each month, gross margin on the Profit and Loss report (P&L) came in around 41 percent. Then the quarterly affiliate settlement arrived, all four platforms invoicing in the same week, totaling $24,000. The next P&L showed gross margin at 30 percent.

The commissions were always owed. They were not in the books until the invoices landed.

Why the timing gap exists

Affiliate programs create a liability the day a sale happens. The customer clicks a link, buys a product, and a commission accrues from that moment. Most affiliate networks will not invoice for 30 to 60 days. Some programs pay monthly, others quarterly, others on demand. Brands running direct affiliate apps through Shopify may receive invoices on irregular schedules depending on the payout settings they chose at setup.

When the books record commissions only when paid, the expense lands in the wrong period. The P&L understates true costs in months with strong affiliate sales and absorbs a catch-up charge when settlement arrives. Neither month is accurate.

Four reasons commissions stay off the books

Commission platforms hold earnings before invoicing. Most affiliate networks hold earned commissions for 30 to 60 days to account for returns and disputed transactions. A commission earned on March 5 may not be invoiced until April 30. On cash-basis recording, that March commission shows up in April. The March P&L looks better than it should.

Multiple platforms create unpredictable timing. A brand running programs on ShareASale, Impact, and a direct Shopify affiliate app has three separate holding periods. Invoices arrive at different times and may cover two or three months of activity in a single bill. Without a monthly accrual entry, the expense has no consistent timing and the P&L becomes irregular even when sales are steady.

Commission rates vary by affiliate and product category. A partner driving sales of a $180 skincare set at 12 percent generates a different commission than one driving a $30 accessory at 8 percent. When commissions are not tracked per partner, the total owed at month-end is hard to estimate. That makes the accrual feel optional, and most brands skip it.

Returns reverse commissions, but the reversal rarely makes it into the books. When a customer returns an order, the affiliate platform reverses the commission. If the original commission was never recorded as an expense, the reversal has nothing to reverse against. If it was recorded, the reversal must reduce both the expense and the liability in the same month the return was processed. Brands that book only on payment typically leave the reversal unrecorded, which silently misstates the cumulative expense.

What the commission record should look like

A skincare brand generated $82,000 in affiliate-attributed sales in March at a 10 percent average rate. Here is how those commissions should move through the books.

March P&L shows $7,600 in commission expense, which is accurate after returns. Cash leaves the bank in April. The expense lives in the month the sale happened.

Why this matters for operating decisions

Two decisions go wrong most often when affiliate commissions are not accrued.

Channel profitability analysis is misstated. A brand tracking P&L by channel, direct versus paid social versus affiliate, compares unequal numbers if commissions are on a cash basis while ad spend is accrued. The affiliate channel appears to carry higher margin than it does. Scaling spend into that channel based on a margin that will drop when the settlement arrives is how brands end up with high revenue and low cash in the same quarter.

Reorder decisions are based on the wrong unit economics. A brand that believes gross margin is 41 percent will reorder with that margin in mind. If true gross margin after commissions is 30 percent, the economics supporting the reorder are wrong. Scaling inventory into an overstated margin is one of the more direct ways a growing brand builds a cash flow problem.

What proper affiliate accrual looks like

For e-commerce clients that run affiliate programs, we record commissions on the last day of every month regardless of when the invoice arrives.

The process is straightforward. We pull the earned commissions report from each active platform at month-end. The total earned goes in as Commission Expense (debit) and Accrued Affiliate Commissions (credit). If any platform reversed a commission on a return during the month, we enter that as a reduction to both the expense and the liability in the same month the return was processed.

When the affiliate payout clears the bank, the liability reduces and cash reduces by the same amount. Expense lands in the month of the sale. Cash moves in the month it actually moves.

We also maintain a simple log of each affiliate partner’s platform, commission rate, and holding period. When a rate changes, the log and the monthly accrual calculation update in the same month.

Best practices for e-commerce operators

A few practices that keep affiliate commission accounting accurate:

• Record a month-end accrual using the platform’s earned commissions report, not the pending payment balance. Earned and pending can differ when commissions are in dispute or still within the return window.
• Keep Accrued Affiliate Commissions as a separate liability account on the balance sheet, apart from general accounts payable. The total owed across all programs should be visible in one line without digging through aging reports.
• Decide once whether commissions belong above or below the gross margin line. If commissions are tied to specific product sales, they belong in cost of goods sold (what it costs to make or buy what you sell). If they function as a general marketing cost, they belong in operating expenses. Apply the decision consistently across all programs.
• Reconcile the liability account balance against each platform’s unpaid commissions report every month. The two numbers should agree within the amount of returns not yet finalized in the platform.
• Enter commission reversals on returns in the same month the return is processed, not when the next platform statement arrives.

Three questions worth asking

1. What is the current balance in your Accrued Affiliate Commissions liability account, and does it match the total unpaid commissions shown across all active platforms?
2. In what month does commission expense appear on your P&L relative to the sale that generated it: the same month, the following month, or only when the invoice arrives?
3. If all active affiliate programs invoiced in the same week, how large would the combined charge be, and is that number reflected anywhere on your current balance sheet?

If those answers are uncertain, the books are recording affiliate costs on a cash basis while the liability is growing untracked in the platform. The fix is a monthly accrual entry and a liability account, not a software change.

If you want a second set of eyes, send us the earned commissions report from any active affiliate platform alongside the P&L for the same period. We will identify whether the liability is properly reflected and show you exactly where the timing gap stands.