Shopify Square integration that keeps the register and the online shop in step

Search this and the first thing you meet is Square’s own comparison page stating there is not a Square Shopify integration, with a developer forum thread saying the same underneath it. Both are accurate and both are answering the payments question: you cannot drop Square in as the card processor at a Shopify checkout without building it yourself, and that has not changed.

The stock question is a different question with a different answer. Square’s catalogue, its counts and its orders are all available to an app you authorise, which is what makes one shared stock count across the counter and the website an ordinary thing to set up rather than a workaround. That half is what this page is about.

So if you came here to run Shopify payments through Square, nothing here helps, and it is better to read that now than three apps later. If you came because the shop floor and the website disagree about how many are left, that is the problem this solves.

Authorize QuickSync in Square, then review the location mapping in QuickSync. Choose the locations whose stock should sync with Shopify. Authorization and location mapping are separate steps; connecting the account does not choose your starting stock for you.

Before Start Syncing, choose the source store and location with the stock you want to use. Check that each mapped destination represents the inventory you intend to sell there. If you ship from one branch, confirm that branch is in the intended connection.

Changing a location mapping does not automatically realign every quantity. Review the new mapping and run an explicit inventory re-sync when you want to align stock again.

Square and Shopify send supported sale and stock changes to QuickSync by webhook. QuickSync processes the change and updates the matching inventory at the locations you’ve connected. Queue processing, retries and each platform’s responses affect the time it takes to reach the other store.

Watch the setup in QuickSync

This 22-second demonstration uses fictional Shopify and Square stores in a demo workspace. It shows the setup choices on Pro and stops at the final review before Start syncing. It does not measure live sync speed.

Start your Shopify and Square setup

Verify your first stock update

1. Choose one test item you control, with the same unique SKU in Shopify and Square. Check Shopify Track quantity, the selected locations and any stock buffer.
2. Select that item and choose the source stock deliberately. Leave Export products off if both listings already exist. Review the scope before Start Syncing: initial alignment can change destination stock.
3. After alignment finishes, change the source quantity from 5 to 4. With no buffer applied, the mapped destination should show 4 after processing; otherwise check the expected quantity after your configured buffer.
4. Check the item in both store dashboards and QuickSync activity. Record when the change was made and when it appeared. Processing and platform responses affect the delay.
5. Repeat in the other direction. If quantities disagree, inspect the SKU, mapped locations and the displayed issue before adding more products.

This is a suggested test procedure, not a recorded customer result. Test only stock you control.

The asymmetry is on the way out instead. Square has no field for a tracking number, so if you post an order that started at the register, the number lives in QuickSync rather than on the Square sale. Shopify takes it normally.

Most of what we connect can only hand orders out. Square is one of the six that can also receive one, which matters when the counter is where the stock physically is. A Shopify sale can arrive in Square as an order, so whoever picks it works from the screen they already use for the day’s takings.

Whether to switch that on is a real choice rather than a default worth accepting. If the counter fills your online orders, routing puts them where the staff already are. If a warehouse fills them and the register is only a register, it adds a record nobody opens.

One precondition either way. An order can only be routed to Square if the items on it exist in Square, matched by SKU, because the lines are built from products we’ve already paired. That’s the same catalogue work the rest of this page describes, which is why order routing is the last thing to turn on and not the first.

Because there is nothing native here, the results for this pair mix two kinds of tool, and the difference between them matters more than the prices do. An automation platform (Zapier is the one that usually comes up) waits for something to happen in one app and performs an action in another. That is genuinely the right tool for a one-way errand: a Square sale adding a row to a spreadsheet, a new Shopify customer landing in a mailing list.

Stock is not an errand. It is a number both shops have to agree on, in both directions, including when they move at the same moment. A counter sale has to take one off the website, a website sale has to take one off the counter, and neither is allowed to write a stale figure over the other on the way past. That is why a dedicated sync app keeps a matched pair of products rather than a list of rules, and it is the part a chain of triggers is not built to guarantee.

Pricing follows from that. Automation platforms bill by task, so each stock change is a unit of cost and the bill grows with how much you sell. Ours goes by shop and catalogue size instead: Lite is $19 a month for two shops and 1,000 items, Pro is $29 for 2,500 items and syncs listings and orders as well as stock, and the figure does not move whether those two shops take 40 orders in a month or 4,000. Shopify and Square is the two-shop case, so it is the smallest plan.