When you first started using Shopify, did you ever find yourself staring at the inventory screen wondering what "Available," "Committed," and "On hand" actually meant side by side? At a glance they look similar, but each one points to something different. And if you keep operating without nailing down the distinction, you'll eventually run into problems like "my sheet doesn't match Shopify" or "I ran the sync but the storefront didn't change."
This article walks through the inventory terms you should pin down first, all in one place. There's nothing complicated here. In fact, the whole point is that simply clarifying the words makes day-to-day operations dramatically easier. Read it as foundation work before we move on to sheet sync.
What is a "location," exactly?
The first concept that comes up when you talk about inventory in Shopify is the location. Plainly put, it's the physical place where the stock actually sits. Your own warehouse, the Tokyo store, the Osaka store, an external 3PL warehouse — all of these can be registered as separate locations in Shopify.
The fundamental rule is that each location holds its own inventory count. So for the same SKU, you can have something like "50 units at the Tokyo warehouse, 10 units at the Osaka store." When a customer places an order, which location fulfills it is decided by your Shopify settings and the order routing logic.
Right after launching a store, most merchants have just one location. So at first it's fine to think of "location" simply as "our warehouse." But once you add stores or start using an external warehouse, you suddenly have multiple locations. The moment that happens, inventory management gets noticeably harder, so it pays to have the idea in your head early.
The three numbers that describe inventory
Shopify's inventory screen shows several similar-looking numbers. The ones most often confused are "Available," "Committed," and "On hand." Let's go through each in turn.
Available
"Available" is exactly what it sounds like: the number of units you can still accept new orders for. When a product page on the storefront shows "in stock," this is the number behind that decision. What customers actually see is less the true remaining count and more this "available" figure.
Committed
"Committed" is the count of units that have already been ordered and are waiting to ship. The customer has completed checkout, but the item hasn't left the warehouse yet — that's the stock that gets tallied here. Committed units are physically still on the shelf, but they can no longer be sold to the next customer.
On hand
"On hand" is the total number of units physically sitting on the shelf. Roughly speaking, Available plus Committed equals On hand (strictly, other statuses like reserved can also factor in). When you do a stock count at the warehouse, what you're counting is the on-hand number.
Here's the key point: when you manage inventory in a sheet and sync it to Shopify, you have to choose which number you're updating. Many sync apps are designed to overwrite "on hand," which then recalculates Available. Others write directly to Available. Which design fits your operation depends on your stock-count cadence and your order flow.
Why turning inventory tracking on matters
Each product in Shopify has a "Track quantity" switch. Unless you turn it on, Shopify won't manage inventory for that product. Sales won't decrement the count, and a sync app trying to write from a sheet won't get its values reflected either.
Only when you tell Shopify "please track inventory for this product" does the quantity field start to mean anything. Forgetting this and then puzzling over "the sync ran but the numbers didn't move" is one of the most common headaches beginners hit.
- Tracking OFF: Shopify holds no inventory count. The item is always sold as "in stock"
- Tracking ON: Shopify manages the count. When it reaches 0, the item is shown as "out of stock"
- Tracking ON + "Continue selling when out of stock": the count can go negative but selling never stops
Before you start sheet sync, we strongly recommend checking that every product in scope has tracking turned on. If a newly added product slips into your workflow with tracking off, one day you'll suddenly be troubled by the mysterious phenomenon of "only this one product's numbers won't line up."
Getting ready for sheet sync from here
Once locations, the three inventory metrics, and the tracking switch are in your head, sheet sync becomes very simple to understand. You take the trio of SKU, location, and quantity from a sheet and write it into the matching inventory level in Shopify — that's the essence of sync.
Flip that around and you'll see: if your sheet's columns don't accurately express these three things, sync won't work. A wrong SKU means the product can't be identified. Without a location, there's no way to know which stock to update. Quantity alone, with no "address" to write it to, won't be accepted by Shopify.
In the next article we'll finally walk through the flow of your "day one sync" using Sync Master. What to do right after install, how to prepare your sheet, the connection test, the actual run, and how to read the logs. With the inventory vocabulary now in your head, that flow should land much more naturally.