Square vs Shopify POS: local simplicity or Shopify omnichannel?

Square sells a register, card processing, hardware, and business software as one package for local merchants. Shopify POS is the in-store side of a Shopify online store. That difference decides most purchases before any feature list does. Both are evaluated here against published criteria; neither product was tested hands-on.

The shop: one storefront, a web store that keeps growing

Picture an apparel retailer with one location. Online orders are a growing share of sales. A customer buys two sizes online, returns one at the counter, swaps the other for a different color, and used an online-only promo code. The owner needs the stock count, the customer's history, the refund, and the books to agree afterward.

The question that settles this shop's choice is simple: where does the web store live today?

Why the web store's platform decides it

If the web store runs on Shopify, choose Shopify POS. The online catalog and the counter then sell from the same product records and the same stock. That shared model is exactly what Shopify POS is positioned on. For this retailer, the return-and-exchange above is the weekly reality, and it is simpler to handle when both channels write to one record than when someone reconciles two.

If the web store runs on another platform, or online sales are a side channel the owner manages by hand, choose Square. Shopify POS earns its keep only through that shared catalog, so without a Shopify store it is just another register. Square's draw is that software, payments, and devices come from one company, which can keep a single-location shop's vendor list short. The question to settle up front: Square sells card processing with the register, and this guide found no Square documentation on whether another processor can be used instead, so ask Square in writing if that matters to you.

What a wrong pick costs this retailer

• Shopify POS without a Shopify web store: staff maintain products and stock in two places, and the last-unit problem (the same jacket sold online and at the counter within minutes) turns into a manual check across two systems instead of a question about one stock count.
• Square while the web store is on Shopify: every online order, return, and promo has to be bridged into the register by an integration or by hand. Ask the integration owner, in writing, which records move, how often, and what happens when a sync fails mid-return. If nobody can answer, that gap is the cost.

The flip case

The pick reverses in one specific situation: the owner is about to move the web store. A shop leaving Shopify for another platform should not buy Shopify POS now. A shop moving onto Shopify should buy Shopify POS, even if online sales are still small, because migrating the register later is likely the more disruptive step.

If the store is planning to open a second or third location with stock transfers, neither product is the obvious answer from this page; compare inventory-led retail systems as well.

One afternoon of checks before signing

Build a small test catalog with a few sizes and colors. Run the online-purchase, in-store return, and exchange sequence above; then sell the last unit in both channels while the store is offline for a few minutes. Note whether each system flags the conflict or lets stock go negative. Export orders, refunds, and customers, and ask your bookkeeper to rebuild the day from the files alone. This evaluation plan was not executed for this page.

On payments, ask each provider which card-security duties stay with your shop under their setup, and use the PCI Security Standards Council merchant resources to confirm what your acquiring bank will expect. A sales-tax setting in either product does not decide how online and in-store sales are taxed; your accountant does.