Consignment software for Square & Shopify
Square rings up the sale and Shopify runs the storefront — but neither one tracks a single consignor, split, or payout, and neither lists your items where buyers actually search. Here is what consignment software for Square and Shopify adds: consignor accounts, automated payouts, and crosslisting to 28+ marketplaces, all on one synced inventory with ResaleOS.
Square and Shopify take payments beautifully but have no concept of a consignor, a commission split, or a payout — and they don’t crosslist your items to outside marketplaces. Consignment software adds that missing layer. ResaleOS gives you consignor accounts, automated splits and payouts, a consignor portal, in-person checkout with Square Tap to Pay, an online storefront, and crosslisting to 28+ marketplaces with automatic delisting — all on one synced inventory, sitting right alongside the Square or Shopify setup you already run.
Adding consignment on top of Square or Shopify
You do not have to rip anything out. The goal is to keep the payment tools you like and add the consignment management and marketplace reach they were never built to do. Here is how the pieces fit together.
Why Square and Shopify alone don’t handle consignment
Square and Shopify are both excellent at the thing they were built for — taking money. Square rings up an in-person sale and Shopify runs a clean online storefront. But neither one knows what a consignor is. There is no field for whose item this is, no commission split attached to a product, and no ledger that tracks what you owe each supplier after a sale.
That means the moment you take goods on consignment, you are back in a spreadsheet. You track who dropped off what, calculate splits by hand, and reconcile payouts manually every month — while your point-of-sale and your storefront quietly go on treating every sale as if the money were entirely yours. It works until you have twenty consignors and a hundred sales, and then it does not.
The other gap is reach. Square and Shopify sell where you already are — your register and your own site. Neither one lists your inventory on eBay, Poshmark, Depop, Mercari or the other marketplaces where buyers are actively searching for exactly the pre-owned items a consignment store carries. Consignment software fills both gaps at once.
Consignor accountsWhat “consignment software” actually adds
Consignment software is the layer that turns "I sold something" into "I sold Maria’s jacket, I keep 40%, and I owe Maria $36." It starts at intake: you add a consignor, set their commission split, and attach their items to their account as you catalog them. Every product now carries an owner and a split rule.
From there it does the accounting you were doing by hand. When an item sells — in person, on your site, or on a marketplace — the split is applied automatically and the consignor’s balance updates. At payout time you settle everyone in a few clicks instead of rebuilding a spreadsheet, and there is an audit trail behind every number.
A consignor portal closes the loop. Consignors log in to see their live items, what has sold, and what they are owed, which cuts the "did my stuff sell yet?" messages to near zero. ResaleOS gives you consignor accounts, automated splits and payouts, and that self-serve portal — the entire consignment side that Square and Shopify simply do not model.
How consignor payouts workSell in person with Square Tap to Pay — one synced inventory
You do not have to give up taking cards on your phone. ResaleOS includes a full Point of Sale with Square Tap to Pay, so you accept contactless cards and digital wallets right on your phone — no extra reader, no separate app to reconcile. Ring up a sale at the counter, at a market, or on a pop-up table, and the payment goes through the same Square rails you already trust.
The difference is what happens after the tap. Because the register shares one inventory with your storefront and your marketplace listings, an in-person sale immediately decrements stock everywhere and applies the consignor split on the spot. There is no separate "in-store" count to reconcile against your online count at the end of the week.
If you are weighing hardware against phone-only checkout, our guide to selling in person with Square walks through both, and the deeper how-to on taking card payments on a phone covers the Tap to Pay setup end to end.
Point of SaleGo beyond your own store — crosslist to 28+ marketplaces
Your Shopify storefront is one shop window. The buyers hunting for a specific brand of jeans or a discontinued handbag are often searching on eBay, Poshmark, Depop, Mercari, Etsy and Facebook Marketplace instead. Consigned inventory — one-of-a-kind, pre-owned, brand-specific — is exactly the kind of item that sells faster the more places it is listed.
ResaleOS crosslists your catalog to 28+ marketplaces from the same products you already have in your register and on your site. AI cataloging drafts the title, description, category and a suggested price from a photo, so getting a consigned item live everywhere takes a minute, not the twenty it would take to type each listing by hand.
The catch with listing a unique item in many places is overselling it. ResaleOS solves that with automatic delisting: the instant an item sells on any channel — or at your Square register — it is pulled from every other marketplace. You get the reach without ever selling the same one-of-a-kind piece twice.
CrosslistingOne synced inventory across register, storefront, and marketplaces
The reason the pieces above hold together is a single inventory underneath all of them. Your register, your online storefront, and every marketplace listing read from and write to the same catalog. Add a product once and it can be sold anywhere; sell it anywhere and it disappears everywhere else.
That one source of truth is also what makes the consignment accounting trustworthy. Every sale — regardless of channel — flows back to the right consignor with the right split, so payouts and per-item margin reporting are built on complete data rather than three disconnected exports you stitch together later. You can see profit per item after the split, and learn which consignors and categories actually earn.
Unified inventoryA quick setup overview
Setup is deliberately short. Connect the sales channels you already use — Square for in-person, your Shopify or ResaleOS storefront for online — and connect the marketplaces you want to crosslist to. Then add your consignors and their commission splits so every item you catalog gets attached to an owner.
From there the day-to-day is: photograph an item, let AI cataloging draft the listing and price, publish it to your store and chosen marketplaces at once, and sell wherever the buyer is. Splits, payouts, inventory sync and margin reporting run in the background. Setting up your online storefront and your consignor portal are each a short, guided flow — not a project.
See plansWant the specifics? See how the online storefront works, how our pricing engine sets prices from real sold comps, or the step-by-step guides to setting up your storefront and selling in person with Square.
Payments you keep, consignment you finally get
Square and Shopify are great at their jobs — they are just the wrong tools for tracking whose item sold and what you owe them, and they were never meant to put your inventory on eBay or Poshmark. Consignment software is the missing half. It turns every sale into a properly attributed, properly split, properly paid-out event, and it takes your consigned goods far beyond your own four walls without risking an oversell.
With ResaleOS you keep the register and storefront you like and add consignor accounts, automated payouts, and crosslisting on top — one synced inventory doing the accounting and the reach at the same time. New to the model? Read how to start a consignment store, or dig into how consignment commission splits work.
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Frequently asked questions
Can I keep using Square or Shopify and still manage consignment?
Yes. ResaleOS is designed to sit alongside the tools you already use rather than replace them. You keep taking payments through Square in person — including Square Tap to Pay on your phone — and you can run a Shopify or a ResaleOS storefront online. ResaleOS adds the consignment layer on top: consignor accounts, automated commission splits, payouts, a consignor portal, and crosslisting — all reading from one synced inventory.
Why don’t Square and Shopify handle consignment on their own?
Because they were built to sell your own inventory, not someone else’s. Neither platform has a native concept of a consignor, a commission split attached to a product, or a payable balance you owe a supplier after a sale. They also don’t crosslist your items to outside marketplaces. That’s the exact gap consignment software fills — tracking whose item sold, applying the split, and keeping what you owe accurate.
How do consignor payouts work?
You set each consignor’s commission split when you add them, and attach their items to their account as you catalog them. When an item sells on any channel, ResaleOS applies the split automatically and updates that consignor’s balance. At payout time you settle everyone in a few clicks with a full audit trail, and consignors can watch it all happen in their own portal. Our guide on how consignor payouts work covers the details.
Will crosslisting cause me to oversell one-of-a-kind consigned items?
No — that’s the whole point of a synced inventory. When you crosslist a consigned item to eBay, Poshmark, Depop, Mercari and the rest, ResaleOS treats it as one unit across every channel. The moment it sells anywhere — including at your Square register — it is automatically delisted from all the others, so a unique piece can’t be sold twice.
Does ResaleOS work for in-person, online, and marketplace sales together?
Yes. That is the core idea: one inventory shared across your Point of Sale, your online storefront, and 28+ marketplaces. A sale in any of those places decrements stock everywhere, applies the right consignor split, and feeds per-item margin reporting. You get in-person Square checkout, an online store, and marketplace reach without three separate systems to reconcile.
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