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.

Approving QuickSync in Square asks you which locations it covers, and it takes catalogue, stock and orders for those and not the others. One shop with one register has nothing to think about. Two branches and a website is where it matters, because what Shopify offers is whatever you included.

The usual mistake is connecting all of them and then wondering why the site is selling something that’s sitting in the other branch. If you post orders from one location only, that’s the one to connect, and the second keeps its own count until you say otherwise.

It’s reversible, but not for free: change the list after a fortnight of trading and every figure in between was worked out from the old one. Ten minutes on this beforehand saves an afternoon of reconciliation later.

Square tells us the moment a card is tapped and Shopify tells us the moment an order is placed, and writing to the other takes under a second either way. Sell the last one at the counter and it’s off the website before the next visitor loads the page.

That isn’t true of every pairing we do, and it’s why this one needs no safety stock. Where a marketplace has to be looked at every couple of minutes, you hold a unit back on the fast movers to cover the window. There’s no window here to cover.

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.