Inventory syncing that keeps one stock count everywhere you sell
You keep one number. Every shop and marketplace you sell on copies it. Something sells in one place and the rest are corrected before the next buyer gets there.
No credit card · included on Lite · nothing changes until you say so
TS-BLK-M · Classic Tee, Black, Mon hand: 41
Shopify41source
Square41+0.4s
WooCommerce41+0.6s
Etsy41+0.5s
Amazon39+1.6sAmazon shows 39 because you told us to hold two back there. Every other shop gets the real number.
You're not careless. You have five shops counting one shelf.
Every shop you sell on keeps its own count and none of them talk to each other. Each one will happily promise the same unit to a different buyer.
The last one goes twice
One unit left. Etsy sells it at 14:02 and eBay sells it at 14:09, because nothing told eBay it was gone. You cancel one, apologise, and take the hit on your seller rating.
So you undersell on purpose
The usual fix is holding half your stock off each marketplace so it cannot happen. That works, and it also means the items sitting in your stockroom are invisible to most of your buyers.
And someone types all day
The other fix is a person and a spreadsheet every morning. It is right at nine and wrong by ten, and it gets worse with every shop you add.
| Counting stock by hand | Stock kept in step |
|---|---|
| The last one sells in two shops within the same hour | The second shop is out of stock before anyone else sees it |
| Typing the same numbers into five shops every morning | One count, sent everywhere, seconds after the sale |
| Holding half your stock back so nothing sells twice | All of it listed everywhere, with a unit or two held back where it matters |
| A cancelled order leaves you one short until someone notices | A refund puts the unit back and tells every shop |
| No way to tell which sale made a number wrong | Every change has the order and the shop that caused it attached |
One sale on Shopify. Nine shops corrected in seconds.
There is no pairing up of shops with each other. Every shop is connected to your one count, so adding another is no harder than the first.
Shopify · order #447114:02:1141 is now the real number. Every shop below is a copy of it, minus whatever you asked us to hold back there.
Square41+0.4s
Clover41+0.5sEtsy41+0.5sWooCommerce41+0.6s
Lightspeed41+0.7s
Squarespace41+0.8s
TikTok Shop41+1.1sAmazon39+1.6s
eBay40+2.1sAmazon and eBay cap how often anyone can send them changes, so they land a second or two behind the rest. Their numbers are lower because two units are held back on Amazon and one on eBay.
The direction shown here is the quick one, because Shopify tells us the moment the order lands. The section below says which shops do that and which ones we have to go and check.
What inventory syncing covers, channel by channel
Stock syncs both ways on every channel we connect to, with one Amazon exception. Speed is where channels differ, so the table shows the exact number for each one.
| Sales channel | Stock sync | How fast we update it | How fast it tells us |
|---|---|---|---|
| Shopify | Both ways | Under a second | The moment it happens |
| Amazon | We always send, and hear back for items you ship | A second or two | The moment it happens |
| Etsy | Both ways | Under a second | Stock every two minutes, orders every five |
| eBay | Both ways | A second or two | We check every two minutes |
| WooCommerce | Both ways | Under a second | The moment it happens |
| Square | Both ways | Under a second | The moment it happens |
| Clover | Both ways | Under a second | The moment it happens |
| TikTok Shop | Both ways | Under a second | The moment it happens |
| Squarespace | Both ways | Under a second | Orders instantly, stock every two minutes |
| Lightspeed | Both ways | Under a second | The moment it happens |
One row per product, one column per shop
Your count is on the left and what each shop currently says is beside it. When two disagree you can see it on the same line, along with when we last put it right.
You can read this screen at a glance. If a number looks wrong, open the product and you get the list of changes that made it: which shop reported the sale, which order it belonged to, and what the count was before it.
That history is the difference between a stock number you trust and one you check by hand every morning. You can download the whole thing as a spreadsheet whenever your accountant asks.
- Safety stock per shop, so the last one or two are never exposed everywhere at once
- Stock split across more than one place, added up or kept separate however you run it
- Anything we cannot match goes to a short review list, and we never guess
- Every change with its reason attached, exportable as a spreadsheet
| Product | SKU | On hand | Amazon | Updated |
|---|---|---|---|---|
| Classic Tee, Black, M | TS-BLK-M | 41 | 39 | 0.4s ago |
| Classic Tee, White, S | TS-WHT-S | 12 | 10 | 2m ago |
| Enamel Mug, Cream | MUG-CRM | 7 | 5 | 9m ago |
| Gift Box, Small | BOX-SM | 3 | 1 | 1h ago |
| Tote Bag, Natural | TOTE-NAT | 0 | 0 | 3h ago |
Refunds, bundles, two-at-once sales: handled
Any tool can sync a normal sale on a normal day. These are the cases that break the others, and how QuickSync handles each one.
Two shops sell the last one at once
The first sale gets it. The second is held and shown to you with both orders side by side, not a silent auto-cancel you discover a week later.
A refund or a cancellation
The unit goes back on the shelf and every shop is told, in the same way and at the same speed as the original sale. This is the one most tools skip, and it is why hand-counted stock drifts upward all year.
A marketplace outage
We hold the update and keep trying until it goes through. Your own count is never wrong in the meantime, you get a single message, not one per retry, and you can send it again yourself.
A bundle or a multipack
Selling a three-pack takes three off the single item, and selling the single takes the three-pack down with it. You set what is inside what once.
Stock in more than one place
A stockroom, a shop floor and a warehouse can be added together into one sellable number, or kept apart so a shop only ever sells what is next to it. You choose per shop.
A number you cannot explain
Every change carries the shop, the order and the count before it. A number never just changes on its own: there is always a reason attached, and you can read it.
Two shops in step in about ten minutes
No developer, no spreadsheet template, and nothing on any of your shops changes until you switch it on.
Connect your first shop
You log in to it the normal way and approve QuickSync on its own screen. Nothing to copy or paste, and you can disconnect from either side whenever you like.
Connect the second
The same again. One shop on its own has nothing to stay in step with, so you need at least two before anything happens.
Let it match your products
We line the catalogues up by SKU first, then by title, and hand you a short list of whatever we could not match. You decide what happens to those. Matching is cleanest when one code means one product everywhere, which is what the free SKU generator is for.
Watch, then switch it on
Leave it watching for a few days and check the numbers agree with yours. When you are happy, let it start making changes, one shop and one direction at a time.
Stock syncing is on the smallest plan
Order volume never changes your bill. Your catalogue size picks the plan, and your plan price covers two connected shops with every shop after that adding it again.
Lite
$19/mo for two shops1,000 items and up to eight connected integrations, with stock kept in step both ways. Everything on this page is included, and nothing on this page needs a bigger plan.
Pro
$29/mo for two shops2,500 items and up to eight connected integrations, and the point at which listings and orders start syncing as well as stock. Most sellers running more than two shops end up here.
Ultra at $69 and Ultra+ at $99 add larger catalogues, price rules and done-for-you setup. Every plan starts with a 14-day free trial and no card.
Questions sellers ask about keeping stock in step
How fast is inventory syncing, really?
Sending a new count to a shop takes under a second nearly everywhere, and a second or two on Amazon and eBay when they are busy. Finding out that a shop sold something itself is the part that varies: seven of the ten sales channels tell us the moment it happens, and Etsy, eBay and Squarespace get looked at every couple of minutes instead. Safety stock is what covers that gap.
Which sales channels does it keep stock in step with?
All ten shops and marketplaces we connect to: Shopify, Amazon, Etsy, eBay, WooCommerce, Square, Clover, TikTok Shop, Squarespace and Lightspeed. Stock moves both ways on every one of them, which is why it is the one job included in the smallest plan. QuickBooks Online is the eleventh integration, and your count is kept in step there too, though as a figure in your books rather than a shop anyone buys from.
How does this stop me overselling?
Two ways. One count goes out to every shop as soon as we know a sale happened, so the window in which a second buyer can reach the same item is seconds, not hours. And you can hold back safety stock on any shop, so it shows nine when you have eleven and the last two are never sold twice. If two shops do sell the last one within the same moment, the first gets it and the second is held for your decision, with no silent oversell.
What about the shops you only look at every couple of minutes?
Nothing about them works differently, it just starts a little later. Etsy, eBay and Squarespace have no way to tell us the second one of their own sales lands, so we go and look on a short timer. Once we have seen it, correcting every other shop takes under a second, or a second or two on Amazon and eBay. Hold one or two units back on those three and the wait stops costing you anything.
Does Amazon stock sync both ways?
Your count goes to Amazon every time it changes, whatever the fulfilment method. Coming back, we pick up Amazon-side changes for the items you ship yourself, and we leave alone anything Amazon holds and ships, because that count is Amazon’s to own. If everything you sell there is fulfilled by Amazon, treat the Amazon direction as one-way.
Which plan do I need for inventory syncing?
Lite, at $19 a month for two shops with every shop after that adding another $19. It covers 1,000 items and up to eight connected integrations with stock kept in step, which is everything on this page. Pro at $29 adds listings and orders. Eight shops is the limit on every plan. Every plan starts with a 14-day free trial and no card.
The two shops you are most likely to be connecting
Each combination has its own guide, because no two channels allow exactly the same things.
Or read about one channel on its own
Every channel has a page covering what it can and cannot do, and how fast it does it.
Connect two shops and watch one correct the other
Make one test sale and watch the other shop’s count drop. If it does not work the way this page describes, you have spent ten minutes and no money.
No credit card required