Your supplier's catalog says $10,000. The invoice says $8,000. And if your books show $10,000 anywhere — as revenue, as a purchase, as a discount line — your financial statements are wrong from the first keystroke. Yet that same week, another invoice offers you 2% off for paying ten days early, and that discount absolutely belongs in your ledger, tracked through a contra account your accountant will ask about at year-end.
Two discounts, opposite treatments. Mix them up and you overstate revenue, misstate inventory cost, and possibly pay tax on income you never earned. Here is how to tell them apart, how to compute the chained percentages suppliers love to quote, and how to book each one correctly.
Trade Discounts: The Price Cut That Never Happened (on Paper)
A trade discount is a reduction from a published list or catalog price, offered to a category of buyer — wholesalers, distributors, high-volume customers, members of a buying group. The supplier prints one price list for everyone, then quotes each customer class a percentage off that list.
The critical accounting fact: the list price is not a transaction. Nothing was ever bought or sold at $10,000. The agreed price was $8,000 from the start, so the books record $8,000 and the $2,000 difference appears nowhere — no discount account, no contra-revenue line, no footnote. Both buyer and seller book the net invoice amount as if the list price never existed:
- Seller: debit Accounts Receivable
$8,000, credit Sales Revenue$8,000. - Buyer: debit Inventory (or Purchases)
$8,000, credit Accounts Payable$8,000.
This surprises people because the word "discount" suggests something to record. Think of it instead as a pricing mechanism: the list price exists so the supplier can maintain one catalog while charging different customer tiers different prices. Your books record what you actually agreed to pay, not the number on the brochure.
One practical consequence: when you compare supplier quotes, always compare invoice prices, never list prices or discount percentages. A 40% discount off an inflated list can easily lose to a 20% discount off an honest one.
Chain Discounts: When the Quote Reads 20/10/5
Suppliers rarely quote a single trade-discount percentage. Instead you see a series — "20/10/5" — called a chain, series, or successive discount. Each percentage applies in turn to the already-reduced price, not to the original list price. That distinction is worth real money: 20/10/5 off a $1,000 list is not a 35% cut.
The math works like this:
- First discount:
$1,000 × (1 − 0.20) = $800 - Second discount:
$800 × (1 − 0.10) = $720 - Third discount:
$720 × (1 − 0.05) = $684
Final invoice price: $684. The total reduction is $316, or 31.6% — noticeably less than the 35% you get by adding the rates.
That 31.6% is called the single equivalent discount: the one rate that produces the same final price as the whole chain. The general formula multiplies the complements (one minus each rate) and subtracts from one:
Single equivalent rate = 1 − (1 − d1) × (1 − d2) × (1 − d3) ...For 20/10/5: 1 − 0.80 × 0.90 × 0.95 = 1 − 0.684 = 0.316, or 31.6%. Order does not matter — multiplication commutes, so 5/10/20 gives the same $684. That is a useful check when a salesperson rattles off a long chain: punch the complements into a calculator in any order and you have the real price.
Why do suppliers quote chains instead of one number? Partly tradition, partly flexibility: each link can represent a different concession (volume tier, full-truckload delivery, annual contract, seasonal promotion), and the supplier can add or remove a link without reprinting the catalog. For your books, though, the whole chain collapses to a single trade discount: record the final $684 and nothing else.
Cash Discounts: The Early-Pay Bargain Written as 2/10, Net 30
A cash discount — also called a sales discount (seller's view), purchase discount (buyer's view), or prompt-payment discount — is a completely different animal. It is conditional: pay early and the price drops; pay on normal terms and it does not. Because the final amount is genuinely uncertain at invoice time, this discount does hit the books.
The standard shorthand is 2/10, net 30 (sometimes written 2/10, n/30): take 2% off if you pay within 10 days of the invoice date, otherwise the full amount is due within 30 days. Variants like 1/15, net 45 or 3/10, net 60 follow the same pattern — discount percent, discount window, full-payment deadline.
Should you take it? Almost always yes, and the reason is the implied cost of skipping it. Passing on 2/10, net 30 means paying 2% more to keep your cash for 20 extra days (day 10 to day 30). Annualized, that is roughly 2% × (365 / 20) — over 36% a year. No business line of credit charges that much; routinely missing cash discounts is one of the most expensive invisible habits in small business finance. Whenever cash flow allows, the early-pay discount beats nearly every alternative use of the money.
Gross Method vs. Net Method: Two Ways to Book the Uncertainty
Because a cash discount may or may not be taken, accountants book the invoice one of two ways. The gross method assumes the discount will not be taken; the net method assumes it will. Both are acceptable, but you must pick one and apply it consistently.
The seller's side: gross vs. net
Suppose you sell $1,000 of goods on terms 2/10, net 30.
Gross method (the common choice). Record the full invoice amount at sale time. If the customer pays within the window, record the discount as a contra-revenue account — Sales Discounts — which reduces revenue on the income statement but never touches the original Sales line:
At sale:
Accounts Receivable 1,000
Sales Revenue 1,000
Paid within 10 days ($980 received):
Cash 980
Sales Discounts 20
Accounts Receivable 1,000Net method (conceptually favored, less common). Record the sale at the discounted amount — $980 — from the start. If the customer misses the window and pays full price, the extra $20 goes to an "other revenue" account, typically Sales Discounts Forfeited:
At sale:
Accounts Receivable 980
Sales Revenue 980
Paid after the window ($1,000 received):
Cash 1,000
Accounts Receivable 980
Sales Discounts Forfeited 20The buyer's side: mirror image
Under the gross method, the buyer records the purchase at $1,000 and credits a Purchase Discounts account (which reduces cost of goods sold) only when paying early. Under the net method, the buyer records the payable at $980 up front, and a missed discount becomes Purchase Discounts Lost — an expense, or arguably a financing cost, that makes chronic late payment visible on the income statement. That visibility is the net method's real virtue: "discounts lost" is a number management can see and fix.
What ASC 606 Says: Cash Discounts Are Variable Consideration
Under current U.S. GAAP, early-payment discounts fall under ASC 606's variable-consideration rules. The transaction price is the amount you expect to be entitled to — not the maximum printed on the invoice. If history says most customers take the 2%, revenue should reflect that expectation from the start, with the estimate updated as facts change.
In practice, this pushes larger businesses toward net-method-style thinking even when their bookkeeping software labels it differently: recognize revenue at the amount you realistically expect to collect. For a small business on simpler books, the gross method remains perfectly defensible — just make sure taken discounts land in Sales Discounts (contra-revenue), not in some expense account where they inflate both revenue and costs.
Trade discounts need no such analysis under ASC 606, precisely because there is nothing variable about them. The list price was never consideration you expected to receive. The $8,000 invoice price is the transaction price, full stop.
Booking Discounts in a Plain-Text Ledger
The distinction maps cleanly onto double-entry bookkeeping. A trade discount simply never appears: you write the invoice amount and move on. A cash discount gets its own postings so the taken (or lost) amount stays visible. Here is the buyer's side of a $1,000 purchase on 2/10, net 30, paid inside the window, in Beancount:
2026-11-01 * "Supplier" "Inventory purchase, terms 2/10 net 30"
Assets:Inventory 1,000.00 USD
Liabilities:Accounts-Payable
2026-11-08 * "Supplier" "Pay invoice within discount window"
Liabilities:Accounts-Payable 1,000.00 USD
Assets:Checking
Income:Purchase-Discounts-Taken -20.00 USDThe checking account resolves to negative $980 — the cash actually leaving — while the $20 discount lands in its own income account, reducing your effective cost of goods. If you had missed the window under net-method-style tracking, that $20 would instead post to an expense account like Expenses:Purchase-Discounts-Lost, where a year-end review of that balance tells you exactly what late payment cost you.
For inventory-heavy businesses, keep the discount accounts consistent across every supplier: one income account for discounts taken, one expense account for discounts lost. Scattered account names are how a 36%-APR leak hides in plain sight.
Five Mistakes That Cost Real Money
- Recording purchases or sales at list price. The list price is a catalog fiction. Booking it overstates revenue (or inventory) and creates a phantom discount that distorts margins.
- Adding chain-discount rates together. 20/10/5 is 31.6%, not 35%. On a
$100,000equipment order, that 3.4-point error is$3,400of mispriced expectation. - Ignoring cash discounts as "only 2%." At 2/10, net 30, skipping the discount is borrowing at roughly 36% annualized. Take every discount your cash flow allows.
- Burying taken discounts in expenses. Sales Discounts is contra-revenue, not an operating expense. Misclassifying it overstates both your top line and your costs.
- Using a different method per invoice. Gross or net, either is fine — but switching back and forth makes period-to-period revenue incomparable and turns your discount accounts into noise.
Your last useful step is a quick audit you can do this week: pull your payables for the last quarter, count the invoices that carried early-pay terms, and check how many discounts you actually captured. If the answer is "most of them," your books already reflect the discipline — just make sure the method is consistent. If the answer is "hardly any," you have found a high-return place to put next month's cash, and your ledger is about to get a new income account.
