Inventory is the number of units you can sell, per item, right now. It goes down with every order, up with every delivery or accepted return, and it has to be the same number on every channel where the item is listed. When it is not, you sell things you no longer have, or you hide things you could have sold.

It concerns every seller of physical goods, from a creator with 12 products in a spare room to a brand with 2,000 SKUs in a warehouse. The mechanics are identical. Only the tolerance for error changes.

What is inventory?

Inventory is the stock you hold for sale, counted per SKU. A hoodie in three colors and four sizes is not one inventory line but twelve, and each one has its own quantity. Inventory management is the set of rules and tools that keep those quantities accurate as goods move in and out.

Several numbers live under the word "stock" and it helps to name them:

  • On hand: physical units in your possession.
  • Reserved or committed: units already sold and waiting to ship.
  • Available to sell: on hand minus reserved. This is what a channel should display.
  • Incoming: units ordered from a supplier and not yet received.

Inventory is not the same as the catalog. The catalog describes what you sell (names, photos, prices, variants); inventory says how many of each you have. It is also different from a backorder, which is an order accepted while the available quantity is zero, and from safety stock, the buffer you keep to absorb surprises.

Why it matters

Stock errors cost money in two directions. Overselling means a refund, an apology and often a lost customer. Overstocking means cash locked in boxes that do not move.

Take a creator selling a $45 candle set. She lists it on a link-in-bio page and a separate store, each with its own stock count. Both show 3 units left. Over one weekend she sells 5 across the two, but only had 3. Two customers get refunded on Monday. On top of the two lost sales ($90), she pays the processing fees on the refunded orders, spends an hour on messages, and one of the two leaves a public review about it.

Now the other direction. A brand orders 600 units of a phone case at $6 because it feels safe. It sells 40 a month. That is $3,600 sitting for 15 months, in a category where the next phone model makes half of it unsellable. The money would have been better spent on 150 units and a second product.

Accurate inventory also drives everything downstream: what you reorder, when, which products to promote, and what your reports say about margin.

How it works

Keeping stock right is a loop of movements and checks. Step by step:

  • Set an opening count per SKU. Count physically, once, and enter it. Do not estimate.
  • Decrement on order, not on shipment. The moment a customer pays, the unit is committed. If you wait until you ship, two customers can buy the same last unit.
  • Increment on receipt. When a supplier delivery arrives, count it against the purchase order before adding it. Short deliveries are common.
  • Handle returns explicitly. A returned item goes back into stock only after inspection. Damaged returns are written off, not re-added.
  • Set a low-stock threshold per SKU. When available stock drops under it, you get a signal to reorder.
  • Cycle count. Rather than one painful yearly inventory, count a few SKUs every week and fix discrepancies as you find them.
  • Keep one source of truth. Every channel reads and writes the same quantity. Separate counts per channel are the root of most overselling.

The formula for the number a channel should show is simple: available = on hand − reserved. Everything else is process.

Benchmarks and examples

  • Stock accuracy. Well-run small stores hit 95% to 98% (that share of SKUs whose system count matches the physical count). Below 90%, you are overselling weekly.
  • Inventory turnover. Units sold per year divided by average units in stock. 4 to 8 is healthy for most consumer goods; under 2 means cash is stuck.
  • Weeks of cover. Current stock divided by weekly sales. 6 to 12 weeks is a comfortable range for products you can reorder in under a month.
  • Dead stock. Items with no sale in 90 days. Keep it under 10% of SKUs, or discount and clear.
  • A creator example. An illustrator holds 25 print designs, 10 to 40 units each. She counts every Sunday, which takes 20 minutes, and sets a low-stock alert at 5 units so a reprint arrives before the last one sells.
  • A brand example. A skincare brand with 60 SKUs sells on its own store and at markets. Each market sale is entered into the same stock system the same evening, so the online store never shows units that left the table that afternoon.

Common mistakes

  • Counting per channel instead of once. Two stock numbers for the same item guarantee they will disagree.
  • Decrementing at shipment. The window between payment and shipping is exactly when double-selling happens.
  • Trusting the supplier's packing list. Count what arrives. A box short by 3 units becomes 3 oversold orders later.
  • Adding returns back without inspection. A scratched item goes back on sale and comes back a second time.
  • Ignoring variants. Tracking "hoodie: 40" hides that size M is at zero and size XS has 18.

Best practices

  • Track at the variant level. Every size, color and pack combination gets its own quantity. There is no such thing as stock for "the hoodie".
  • Reserve at payment. Configure your store so the unit is committed the instant the order is paid.
  • Set reorder points from real lead times. If your supplier takes 3 weeks and you sell 10 a week, reorder at 30 units plus a small buffer, not when you hit zero.
  • Count something every week. Ten SKUs every Monday keeps accuracy high without ever needing a full-day stock take.
  • Hide or mark sold-out items automatically. A product that says "sold out" loses one sale; a product that takes an order it cannot fill loses a customer.
  • Review slow movers monthly. Anything with no sale in 90 days gets a discount, a bundle, or a decision to stop reordering.
  • Write down the process. One page that says who counts, when, and what to do on a discrepancy. It matters as soon as a second person touches the stock.

In Roctify

Stock in Roctify is tracked once, in the shared catalog, at the level of each product and each variant. Your link-in-bio page and your online store read the same quantity. When an order is paid on any channel, the quantity goes down immediately, and a product that reaches zero is shown as sold out everywhere at the same time. There is no per-channel count to reconcile.

Physical products carry stock, variants, shipping and tax settings, and orders from every channel land in one list, so a return or a manual adjustment is made in one place. Reports and exports on the Pro plan let you pull quantities and sales into a spreadsheet to compute turnover and weeks of cover per SKU.

FAQ

How often should I count my stock?

Count a small set of SKUs every week rather than everything once a year. A creator with 30 SKUs can count all of them in 20 minutes on a fixed day. A store with 500 SKUs should count 20 to 30 a week, starting with the best sellers, because those are the ones where an error costs a sale.

What is the difference between inventory and stock?

In everyday selling, none. Both mean the units you hold for sale. In accounting, "inventory" sometimes also includes raw materials and work in progress, while "stock" refers to finished goods. For an online store that buys finished products, the two words are interchangeable.

Should I show the remaining quantity to customers?

Show it when it is low and true. "Only 3 left" on a product that really has 3 left raises conversion. Showing it on every product, or showing a fake number, trains customers to ignore it. Most stores display the count under a threshold such as 5 units and say nothing above it.