Square and Shopify POS are the two names most small businesses reach for, and both are genuinely good. But there's a third option — a custom-built POS — that occasionally makes more sense than either. This comparison lays out honestly where Square and Shopify POS win, and the narrow set of situations where building your own is actually the smart move rather than an expensive vanity project.
Spoiler: for most businesses, one of the ready-made options is the right answer. Let's see if you're the exception.
Square and Shopify POS are excellent and cheap to start. A custom POS earns its cost only when your needs or your scale genuinely outgrow them.
Square: simple and flexible
Square is famously easy — free software, cheap hardware, and simple pay-as-you-go transaction fees with no monthly commitment. It suits cafés, market stalls, small retailers, and service businesses that want to start taking card payments today. The trade-off is that its fees, taken on every sale, add up as your volume grows.
Shopify POS: best if you sell online too
Shopify POS shines when you already sell online with Shopify, because it unifies your in-store and online inventory, customers, and reporting in one place. For an omnichannel retailer, that single source of truth is a real advantage. If you don't sell online, though, much of that benefit is wasted and Square may be simpler.
Custom POS: for the exceptions
A custom POS is built around your exact operation, with no per-transaction platform cut and no features you don't need. It's the right call only in specific cases: unusual workflows the ready-made systems can't model, deep integration with custom back-office software, or a scale where transaction and per-terminal fees dwarf a one-time build. Our off-the-shelf vs custom software guide unpacks that trade-off.
How to choose
- Just want to take payments simply? Square.
- Already selling online with Shopify? Shopify POS.
- Unusual needs or huge volume? Consider custom — but do the math first.
- Unsure? Start with Square or Shopify POS; they're cheap to try and hard to regret.
Frequently Asked Questions
Is Square or Shopify POS better?
It depends on whether you sell online. Square is simpler and great for taking payments in person with no monthly commitment. Shopify POS is better if you already sell online with Shopify, because it unifies your in-store and online inventory, customers, and reporting. If you're purely in-person, Square is usually simpler; if you're omnichannel, Shopify POS wins.
When is a custom POS worth building?
A custom POS is worth it only in specific cases: when you have unusual workflows the ready-made systems can't handle, when you need deep integration with custom back-office software, or when your transaction and per-terminal fees at high volume outweigh a one-time build. For most businesses, Square or Shopify POS is cheaper and better.
Does a custom POS avoid transaction fees?
It can reduce the platform's cut, but you'll still pay a payment processor to handle card transactions, since someone has to move the money. What a custom POS avoids is the extra per-transaction or per-terminal fee that platforms add on top. At high volume that saving is meaningful; at low volume it rarely justifies the build cost.
How much does a custom POS cost compared to Square?
Square costs almost nothing to start, with fees taken per sale, while a custom POS is a development project that can run from many thousands to tens of thousands of dollars. Custom only becomes financially sensible at a scale where the ongoing platform fees you'd pay Square or Shopify would exceed that upfront build cost over a few years.
Can Square and Shopify POS handle multiple locations?
Yes, both support multiple locations and registers, with reporting that rolls up across your business. This covers the needs of most growing retailers and hospitality businesses. If your multi-location requirements are genuinely unusual — beyond what their location features allow — that's one of the few cases where a custom system might be justified.
Should a new small business build a custom POS?
Almost never. A new business should start with Square or Shopify POS, which are cheap, reliable, and quick to set up, and learn what it actually needs. Building custom before you understand your operation risks paying for the wrong features. Revisit the custom question only once you've clearly outgrown the ready-made systems.
Deciding between a custom POS and Square or Shopify?
We'll run the numbers with you and recommend the ready-made option when it wins — which is often. Book a free 30-minute call.
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