Guide
Sell-in vs sell-out: what is the difference?
Updated 13 October 2026
Sell-in is what a supplier sells to a retailer. Sell-out is what that retailer then sells to shoppers. Sell-in tells you what you shipped; sell-out tells you whether it moved. The difference between the two is the stock building up, or running down, in the retailer's stores and warehouses.
Two numbers for the same product
Every product a supplier sells through a retailer has two sales numbers. Sell-in is recorded by the supplier: orders received, invoices raised, cases delivered. Sell-out is recorded by the retailer: units scanned through the tills. They describe the same product, but at different points in the chain and often in different weeks.
Sell-in
- Supplier to retailer
- Your invoices and deliveries
- Counted in cases, at your price
- Lumpy: follows the retailer's orders
Sell-out
- Retailer to shopper
- The retailer's till data
- Counted in units, at shelf price
- Smoother: follows real demand
How the two numbers fit together
Over any period, what went in has to go somewhere. Sell-in equals sell-out, plus the change in stock held by the retailer, plus anything lost along the way: damages, theft and returns. If sell-in runs ahead of sell-out for long, stock is piling up. If sell-out runs ahead, the retailer is selling down its stock and an empty shelf is coming.
- Sell-in higher than sell-out: stock is building in stores and distribution centres. Expect smaller orders next, and possibly returns or markdowns.
- Sell-out higher than sell-in: the retailer is living off its stock. Good demand, but out-of-stocks follow unless orders catch up.
- Both rising together: real growth, with the pipeline keeping pace.
Why sell-in alone can mislead
A strong month of sell-in feels like success. But if a big order was simply stock-building ahead of a promotion, or a new listing filling the shelves for the first time, the sales have not happened yet. A launch can show excellent sell-in and then disappoint at the till. A promotion can look like growth on your invoices and then be paid for in returns three months later.
The reverse is also true. Sell-in can drop because the retailer is running down its stock, while shoppers are buying as much as ever. Without sell-out, a supplier can cut a forecast for a line that is actually doing well.
Weeks of stock: turning the gap into one number
The most useful way to read the gap is to divide the retailer's stock on hand by the weekly rate of sell-out. That gives weeks of stock in the channel. Too few weeks and shelves will empty before the next delivery. Too many and the next orders will shrink. Watching this number per retailer and per product turns two confusing sales lines into one clear signal.
Using both well
- Forecast from sell-out, not sell-in, because sell-out is closer to real demand.
- Judge promotions on sell-out during and after the promotion, not on the order that came before it.
- Judge a new listing on how fast it sells per store, not on the first fill.
- Take both to the buyer: what you shipped, what sold, and what is sitting in their stores.
How OuterJoin helps
Sell-in lives in your own systems. Sell-out and retailer stock live in each retailer's portal, in its own format. We collect the retailer side, match it to your products and stores, and put it next to the numbers you already know, so the gap is visible every day instead of every quarter.
Common questions
- Is sell-out the same as consumer sales?
- Yes. Sell-out is sales to the end consumer, as recorded at the retailer's tills. Sell-in is sales into the retailer.
- Why do sell-in and sell-out never match in a given month?
- Because the retailer holds stock. Orders arrive in batches, while shoppers buy every day. Over a long enough period they track each other; in any single week or month the difference is stock moving in or out of the retailer.
- Which one should sales targets be set on?
- Most suppliers are paid on sell-in, so targets usually sit there. But sell-out is the better early warning: a sell-in target hit by filling the channel will be paid back in later months.