How to Sync Inventory Between Square and Etsy (and Stop Overselling After Market Day)

Picture Sunday, 6:40 p.m. Nadia, a composite candle maker rather than a real seller, is folding the tablecloth at the end of a good market. She sold her last three cedar candles before lunch, rang every one through Square, and drove home happy. Then her phone buzzes. It's an Etsy order for a cedar candle, and Etsy still lists two in stock.

She has none. She now gets to write the apology message, refund the buyer, and hope the next one isn't the same.

That's what happens when two sales channels each keep their own stock count and neither tells the other. There are three ways to sync inventory between Square and Etsy:

1. Etsy's built-in Square connection. It's free and it handles the most common case, but it only syncs one way: Etsy listings go into Square's point of sale, and Square-only items and edits never reach Etsy.
2. A multichannel sync app that keeps the two catalogs matched, often with Square as the main store.
3. One inventory system that both channels connect to, so a sale from either side comes off the same count.

If Etsy is your main shop, start with the first option and find out quickly whether you've outgrown it. Here's what each one actually does, where each breaks, and a step-by-step setup for the third.

Why Square and Etsy disagree about your stock

Square keeps a count for every item at every Square location. Etsy keeps a quantity on every listing. Nothing in either system knows the other exists until you connect them.

So a candle that sells at your booth comes off Square's count and nowhere else. A candle that sells on Etsy at 2 a.m. comes off Etsy's quantity and nowhere else. If you update the other side by hand, it stays in step for exactly as long as you remember. On a market day, with a line at the booth, nobody remembers.

The gap is widest on the items you're most likely to oversell: the bestseller you made twelve of, and the one-of-a-kind piece you only have once.

Option 1: Etsy's built-in Square connection (free, one direction)

Etsy has a native Square integration under Shop Manager → Sales Channels → Sell in person. According to Etsy's help article on using Square (opens in new tab), you sign up for Square or link an existing account, then sync your Etsy listings into Square, where they appear in the Square Point of Sale app. Etsy says the sync "will cause any items sold in-person to be reflected in your online inventory."

That covers Nadia's Sunday. If her cedar candle listing had been synced, the three market sales would have lowered her Etsy quantity.

Setting it up takes a few minutes:

1. In Shop Manager, open Sales Channels, choose Sell in person, and sign up for Square or link your existing account.
2. Pick the Square location you ring up market sales on. Etsy links one.
3. On the Square sales channel page, choose Sync your Listings. Etsy's article puts the sync time at up to a minute per 300 listings.
4. At the market, ring up the synced items in the Square app, so each sale knows which listing it came from.
5. Sync any new Etsy listings into Square before each market.

Read the limits before you rely on it. All of them come from the same Etsy article:

• It only goes one way. Etsy states that "Syncing from Square to Etsy is not supported at this time." Items you add or edit in Square don't reach Etsy, so the Etsy listing has to be the master record.
• It links one Square location. Sellers with several Square locations pick one to connect to the Etsy shop.
• Physical listings only. Shops with only digital listings get a sync error.
• There's a variation ceiling. Etsy cites a 250-variation limit (opens in new tab) on the Square side; go over it and the sync fails.
• An unsynced item costs you. Etsy charges no extra fee for synced items sold through Square, but when you sell an item through Square that isn't synced with your listings, Etsy charges $0.20 per transaction (opens in new tab), billed as a "Square manual" fee.
• It covers the US (not US territories), the UK, Canada and Australia.

It's enough when: Etsy is your main shop, you sell in person from one Square location, and nearly everything on your table also has an Etsy listing.

You've outgrown it when: you keep market-only items in Square that never go on Etsy, you run more than one Square location, or you sell through Square Online as well as the register and want those orders handled from the Square side.

Option 2: A Square–Etsy multichannel sync app

Third-party tools sit between the two platforms and keep the catalogs matched. LitCommerce's Square–Etsy page (opens in new tab) shows one common shape: Square is set as the "Main Store," Etsy becomes a connected channel, stock counts sync between the two, Etsy orders can be imported into Square, and you can hold back a percentage of your Square stock from Etsy.

Two things to check before you pay for one.

First, the sync interval. That interval is how long a sold item stays buyable on the other channel, and a headline won't tell you what it is. LitCommerce's page is headlined "Sync Inventory in Real Time," yet its body gives two figures (as of October 2026): "every 60 minutes" in several places, and "every 15 minutes" in one of its setup guides. Ask the vendor which applies to your plan.

Second, what the app counts. A sync app matches finished-goods counts between two catalogs. It doesn't know that the 24 candles came from one pour of wax, or what each one cost to make. If those questions matter to you, a sync app keeps the numbers matched but doesn't tell you what's behind them.

It's enough when: Square is your main record, you want product details (titles, prices, descriptions) pushed to Etsy too, and costing lives somewhere else.

Option 3: One stock count that Square and Etsy both read

The third setup moves the stock count out of both sales channels and into an inventory system that both connect to. Square and Etsy stop being the record and become two places that sell from it. A sale on either side comes off the same count, and the system pushes the new number (sends it out) to both.

This is how Ardent Seller's Square integration and Etsy integration work together. Each product is one inventory item, linked to its Square item and its Etsy listing. Square sales and Etsy orders import about every 15 minutes, and per the Square sync docs, a sale on one channel reaches the other channel's auto push listings (step 4) within about 15 minutes.

It's worth it when: you make what you sell, you sell from more than one place, and you want the count, what each unit cost, and both channels kept in step in one place.

The playbook below is written for that setup. Steps 1 to 4 are done once; steps 5 and 6 are the routine for every market weekend.

Step 1: Decide where each channel sells from

Before anything syncs, answer one question: when you're at a market, which stock is Etsy allowed to sell?

The cleanest answer uses two locations. Your workshop holds everything at home and is the stock Etsy sells from. Your market location holds what's in the car or on the table, and it's mapped to the Square location you ring up market sales on. In Ardent Seller, Etsy orders land at the connection's default location (the workshop), and Square sales land at whichever location is mapped to the Square location where the sale was rung up.

Set it up this way and Square market sales never touch the number Etsy sees, because that stock was never offered on Etsy. Overselling between two channels happens when both sell the same physical stock, so separating that stock closes the gap before any buffer is involved.

If you only have one location, that's fine. Both channels draw from the same pool, and step 3 matters more.

Step 2: Link each listing to one item

Every Etsy listing and every Square item needs to point at the same inventory item, or a sale has nothing to deduct from. Matching SKUs do most of the work: Etsy listings and Square items whose SKU matches one of your inventory items link automatically, and anything left over gets linked by hand on the connection's Listings tab.

If your SKUs are inconsistent ("CS-9OZ" on Etsy, "cedar smoke 9" in Square), fix them in Etsy and Square themselves first. The sync reads SKUs from those catalogs and doesn't rewrite them. The free SKU Naming & Barcode System Starter Kit gives you a naming scheme to apply across both catalogs in one sitting.

Watch the variations. A candle sold in three sizes is one Square item with three variations, and one Etsy listing with three variations. Neither pushes cleanly today: Etsy links a whole listing to one item and the push sets every variation to the same count, and Ardent Seller doesn't yet update a Square item that has more than one variation. So keep multi-size items on Manual only on both channels and update their counts by hand. The automatic setup below is for items sold in one size.

Step 3: Set a safety buffer on the Etsy side

No sync is instant. Between a sale on one channel and the update on the other, the item is still buyable. A safety buffer holds back a few units to cover that gap: Ardent Seller pushes your on-hand count minus the connection's buffer, so a buffer of 1 means Etsy shows 4 when you hold 5.

The buffer is set per connection, not per item, and Square and Etsy each have their own. Put it where the risk is. At the booth you can see what's on the table; Etsy sells unattended at 2 a.m. So leave Square at 0 and decide Etsy's buffer with one question: does anything else sell from the stock Etsy sells from?

• No. With the two-location split from step 1, market sales come off the market location and never touch Etsy's count. If nothing else sells workshop stock, a buffer of 0 is reasonable.
• Yes. With one location, or with Square Online or a studio register selling workshop stock, both channels share a pool and the gap is about 15 minutes. At 6 Etsy sales a week, an Etsy order landing in those 15 minutes is unlikely. The exposure is the last unit: when your last cedar candle sells at the register, those 15 minutes are the only time Etsy can sell one you don't have. A buffer of 1 means the last unit can only sell in person, and Etsy's count reaches zero one unit early. A listing that gets there stops syncing until you reactivate it (step 5), so after you restock, renew it on Etsy if Etsy shows it as sold out, then click Reactivate Listing in its details in Ardent Seller.

One catch. Because the buffer covers the whole connection, a buffer of 1 also hides every listing you hold just one of, so one-of-a-kind pieces drop off Etsy entirely. A shop built on one-of-a-kinds should keep Etsy's buffer at 0 and rely on the location split: transfer a piece to the market location when you pack it (step 5) and Etsy can't sell it while it's away. Its Etsy listing goes to zero, though, so if it comes home unsold, reactivate the listing before you transfer it back (step 6).

Step 4: Turn on auto push, one listing first

In Ardent Seller, newly linked listings start on Manual only, which leaves your Etsy and Square counts alone until you push by hand. That's deliberate: if a count is wrong when you link, you want to find out on one listing, not your whole shop. It also means nothing in step 5 reaches Etsy until this step is done.

Each item has two links, its Etsy listing and its Square item, and each has its own setting. Pick one single-size item you've just counted on the shelf, with at least a few more units than Etsy's buffer so the test never sends a zero. Open its listing on each connection's Listings tab and switch both to Auto push. Record an adjustment taking its workshop count down by one, check that Etsy drops, then record an adjustment putting it back. Ardent Seller only updates the Square locations you've mapped, so to test Square with the step 1 split, transfer one unit to the market location, check that the mapped Square location's count rises, then transfer it back.

Before switching everything, recount anything you're unsure of. Auto push sends counts out exactly as they are, and a listing pushed to zero stops syncing (step 5). Then open Settings on both the Etsy and the Square connection, set the default to Auto push, and turn on Also apply to listings already linked. That switches every linked listing, so afterward set two kinds back to Manual only. Multi-size items from step 2 stay there for now. The Etsy listings of items at or below Etsy's buffer stay there until you restock: in the meantime nothing you record reaches those listings, so whenever one of those items' counts changes (a sale on Square, or packing one for the market in step 5), update its Etsy quantity by hand. Once restocked, switch them back to Auto push in their listing details.

Step 5: Move market stock before you load the car

The night before the market, record a transfer of everything going into the crates from the workshop to the market location. The workshop count drops, and on the next push Etsy's quantities drop with it. Etsy is now selling only what's staying home.

This is the step that would have saved Nadia's Sunday.

Watch anything you pack all of. When a push takes an Etsy listing to zero, Ardent Seller's Auto-deactivate out of stock setting (on by default, in the connection's Settings) stops syncing that listing until you reactivate it, so the count won't come back on its own when the stock does. The simple way around it is to keep more units at home than Etsy's buffer. Otherwise, reactivate those listings after the market, as step 6 shows.

Doing it by hand? It depends on what's connected. With no connection at all, lower each Etsy listing by what you pack, and add the unsold units back when you get home. With Etsy's Square connection, skip it: in-person sales of synced listings already come off Etsy, so lowering Etsy by hand as well takes every sale off twice.

Step 6: Bring the unsold stock home

When you unpack, do it in this order:

1. Give the last Square sales about 15 minutes to import, then check the sales list's Needs attention filter for anything that didn't match an item. That's where Square custom-amount sales end up (see below).
2. Adjust the market location's stock by hand for any of those sales.
3. For any Etsy listing that went to zero while you were out, check it on Etsy and renew it there if Etsy shows it as sold out, then click Reactivate Listing in its details in Ardent Seller.
4. Count what's actually in the crates and record a transfer of that from the market location back to the workshop. Etsy's quantities go back up on the next push.
5. If the market location still shows stock you didn't bring home, record an adjustment bringing it to zero, so next weekend starts clean.

Twenty minutes on Sunday night, most of it waiting for the last sales to import, and Monday's Etsy shop is right.

Four ways Square–Etsy sync still breaks

Even a well-set-up sync has gaps the steps above don't close on their own. Here are four to watch for.

Custom amounts at the register. Typing "$18" into Square instead of tapping the item rings up the money but tells nothing which candle left the table. In Ardent Seller, a custom-amount line keeps its revenue but deducts no stock. Fix: tap items, never amounts, and adjust stock for any custom-amount sale before you transfer the leftovers home (step 6).

Correcting the same sale twice. Say an item sold before it was linked and you adjusted its stock by hand. When you link it later, its earlier Square sales deduct stock automatically, and the item comes off twice. Fix: the Square sync docs say to reverse that hand adjustment first, then link.

Square Online orders that are still open. Only completed Square sales import. An online order that's paid but still open in Square doesn't come off the count until you complete it. Fix: complete Square Online orders when you pack them, not when they ship.

The one-location weekend. With a single location, a market sale and an Etsy order draw from the same pool, and the sync gap is all that separates them. Fix: set up the second location from step 1. If you'd rather not, set Etsy's buffer to 1 and leave it there, unless most of your listings are one-of-a-kind. A buffer of 1 hides those (see step 3), so for that shop the second location is the only fix.

Which setup fits your shop

• Etsy is home base and the market is occasional: start with Etsy's built-in Square connection. It's free. Make the Etsy listing the master record and sync any new Etsy listings into Square before each market.
• Square is home base and Etsy is a second storefront: a multichannel sync app fits, especially if you want titles and prices pushed to Etsy too.
• You make what you sell and want one count, its cost, and both channels in step: use an inventory system that both channels read from.

For Nadia, the third setup is the one that fixes that Sunday: two locations, a Saturday-night transfer, and Etsy drops to what's left at home. The cedar candles still sell out. They just don't sell out twice.

If that's the setup you want, see how Ardent Seller works for Square sellers. Each connection works on every plan. Running Square and Etsy together needs the Artisan plan or higher, or pay-as-you-go, because each connected shop takes one of your plan's shop slots; the pricing page lists how many each plan has.

Related reading

• Square vs. Ardent Seller for Makers — What Square does well at the register, and what it doesn't know about how your products get made.
• Best Inventory App for Etsy Sellers — The tools Etsy sellers compare when the shop outgrows a spreadsheet, side by side.
• How Much Inventory for Your First Craft Fair — How many units to pack, which decides how much stock you move off Etsy in step 5.
• Multi-Location Inventory Tracking — The workshop-and-market split from step 1, applied to every place you keep stock.

Free resources

Two free downloads that pair with a two-channel setup:

• SKU Naming & Barcode System Starter Kit — A naming scheme to apply to your Square items and Etsy listings before you link them, so they match automatically.
• Craft Show Prep and Profit Tracker — A packing checklist and post-show reconciliation page that line up with the transfer-out and transfer-back steps above.