How to connect Square to Shopify for payments (honest answer)

Short answer: No — you cannot add Square as a payment gateway on your Shopify online checkout. Square is not on Shopify's payment provider list, and no app adds it. What merchants actually mean by "connect Square to Shopify for payments" is a hybrid setup: Shopify processes online orders, Square processes in-person ones, and you connect everything around the two payment rails.

This post explains why the direct connection does not exist, what you can genuinely connect, and which pieces break if you do nothing.

Why Square is not a Shopify gateway

Shopify and Square are competitors at both ends of the stack:

Square sells Square Online, a website builder competing with Shopify.
Shopify sells Shopify POS, an in-person product competing with Square.

Neither company has a commercial reason to let the other own its checkout. This is a business decision, not a technical gap — which is why it has not changed and probably will not.

So when a blog or AI assistant tells you to "install the Square payment app in Shopify," it is describing something that does not exist. Check Shopify's own gateway directory before you spend an afternoon looking.

What "connecting Square to Shopify" can actually mean

Five different things get called the same thing. Only some are possible:

What you want	Possible?	How
Square as Shopify online checkout	No	Not offered; no workaround
Square Reader on Shopify POS	No	Shopify POS requires Shopify hardware/gateway
Sync products and inventory	Yes	Connector apps (App Store)
One loyalty balance across both	Yes	Payment-webhook ledger (this is SamePoints)
Combined revenue reporting	Partly	Export both, or pipe into a BI tool

Most people searching the payments phrase actually want rows 3 to 5. They assume payments must be unified first. They do not.

The hybrid setup retailers actually run

This is the configuration most Shopify + Square merchants land on:

Shopify owns the online store. Use Shopify Payments where available — a third-party gateway adds a per-transaction fee on top of the processor's own rate.
Square owns the counter. Square Reader, Register or Terminal, with Square's in-person rate.
Catalog syncs one direction. Pick one system as the source of truth for products — usually Shopify — and push to the other. Two-way sync on the same SKU set invites conflicts.
Customer identity is captured at both tills. Email online, phone number in store. Without this, nothing downstream can match a shopper across rails.
Loyalty runs on one ledger that listens to both payment streams.

Note what is not in that list: a shared payment processor. You will reconcile two payout streams into your accounting, and that is normal for hybrid retail.

What breaks if you connect nothing

Running both platforms with no layer between them produces four predictable failures:

Split loyalty balances. Square Loyalty counts in-store spend. Your Shopify loyalty app counts online spend. Same customer, two totals, and a support conversation you cannot win. We covered the mechanics in does Square Loyalty sync with Shopify.

Duplicate customer records. The same person appears as an email in Shopify and a phone number in Square. See merging duplicate loyalty customers.

Inventory drift. Sell the last unit at the counter and online at the same time, and one of those customers gets an apology email.

Reporting you cannot trust. Neither dashboard shows total revenue per customer. You end up with a spreadsheet.

The first two are the expensive ones, because they are visible to customers.

Where the loyalty layer fits

Loyalty is the piece that most obviously should cross the two rails — a membership that only works in one channel is not a membership.

The workable approach ignores the payment gateway question entirely and listens to money events on both sides:

Shopify orders/paid webhooks for online sales.
Square payment and refund webhooks for counter sales.
One immutable ledger applying the same earn and refund rules to both.
One display surface — for most DTC brands, the Shopify storefront.

This works precisely because it does not need a shared processor. Both platforms emit payment events; you only need something listening to both.

Tradeoff worth stating plainly: with this model, Square Loyalty should be turned off, or both systems award points on the same in-store sale. Customers then check balances on your website rather than the Square Customer Display. See turning off Square Loyalty.

Operator checklist

Before you build anything:

Confirm you are not waiting on a Square gateway that is not coming.
Decide which system is the source of truth for products.
Turn on phone capture at Square checkout — this is what makes matching possible.
Decide where customers see their balance, and train staff to say it out loud.
Pick one earn authority so no sale is counted twice.

If you are still choosing between the two POS systems rather than running both, Shopify POS vs Square POS compares them on the loyalty dimension specifically.

What is SamePoints?

SamePoints unifies loyalty points across Shopify and Square. It does not touch payment processing and does not require a shared gateway — it listens to Shopify order webhooks and Square payment and refund webhooks, keeps one immutable ledger, and syncs the balance to Shopify customer metafields so your storefront can display it. Customers claim Shopify gift cards from the storefront launcher once they hit the threshold. It is built for retailers running Shopify online and Square in store.

Install from Shopify Admin · Square setup guide

FAQ

Can I use Square as a payment gateway on Shopify?

No. Square is not available as a payment provider for Shopify checkout, and no third-party app adds it. Shopify and Square compete directly in both e-commerce and in-person payments, so this is a commercial decision rather than a technical limitation.

Can I use a Square Reader with Shopify POS?

No. Shopify POS works with Shopify's own card readers and payment processing. Square hardware is tied to Square's payment stack. Running both means two sets of hardware, or choosing one system for in-person sales.

Is there any workaround to accept Square payments on a Shopify store?

Not for the standard checkout. Some merchants send Square invoices or payment links for specific orders handled manually, but that is a separate transaction outside Shopify checkout — the order will not carry payment status in Shopify, and it does not scale.

Do I need Square and Shopify to share payments before I can unify loyalty?

No, and this is the most common misconception. A loyalty ledger listens to payment events from each platform independently. Both Shopify and Square emit webhooks when money moves, which is all a unified points system needs.

Will I pay two sets of processing fees?

You pay each platform's rate on the sales it processes — Shopify's rate online, Square's rate in store. That is not double-charging. The fee to avoid is Shopify's additional third-party gateway fee, which applies if you use a non-Shopify-Payments provider online where Shopify Payments is available.

Does inventory sync between Square and Shopify automatically?

Not natively. Connector apps in the Shopify App Store handle catalog and stock sync, and they are separate from loyalty. Pick one system as the source of truth before enabling any sync.