Square - Integration Set up
Rex's Square integration lets you take payments through your Square account — online card payments, Square invoices, and in-person payments on a connected handheld card reader. This guide covers connecting Square, setting it up per venue, and pairing a handheld device.
Before you start
- You'll need admin access in Rex and a Square account.
- Setup has three parts: connect Square once at the account level, then enable it and map a Square location for each venue, then (optionally) pair any handheld readers.
- Square must be activated for your account. If you don't see it, contact support.
Step 1 — Connect your Square account
Open the Square integration
Find the Square card on the Integrations page.
Click Connect
A Square authorization window opens.
Approve the connection
Log in to Square and approve the requested permissions. The window closes automatically and the Square card now shows Connected.
You only do this once for your whole account.
Step 2 — Enable Square for each venue
For every venue that should use Square, open the venue's Venue Info and find the Square section.
| Field | Description |
|---|---|
| Enable Square | Turns Square on for this venue. Required for any payments or readers. |
| Location ID | Which Square location this venue maps to. Determines where payments and readers are registered. |
| Fallback Item | Recommended. A backup Square catalog item Rex uses if a mapped item can't be found at payment time — helps avoid errors right after you edit items in Square. |
| Cash App Enable | Optional. Lets guests pay Square invoices with Cash App Pay. |
| Bank Account Enable | Optional. Lets guests pay Square invoices by bank transfer (ACH). |
Step 3 — Set Square as the payment processor
If this venue should process payments through Square, open the venue's Payment Settings and choose Square as the processor. No keys or secrets are needed — Square is authorized through the connection in Step 1.
Step 4 — Add a connected handheld device
You can pair a Square handheld reader (Square Terminal, or the Square app on a supported device) so staff can take in-person card payments tied to the venue's Square location.
Need help setting up the device itself? See Square's guide: Set up Square Terminal.
Readers are paired to the venue's Square location. Before creating reader codes, make sure Square is connected (Step 1) and the venue has a Location ID set (Step 2).
Open Payment Options
Find the Payment Options card under Host Settings.
Turn on Square Card Reader
If the toggle is greyed out, Square isn't connected for this venue yet — finish Steps 1–2 first.
Name the new reader
Under New Reader Code Name, type a label so you can recognize the device (for example, Bar iPad or Front Desk Terminal).
Generate a pairing code
Click Create code. A new row appears showing the reader's Name and a Code.
Pair the device
On the physical handheld, open the Square app (or Square Terminal), sign in to your Square account, and enter that Code when prompted to pair a device.
Save the venue
Back in Rex, click Save changes. The device is now paired to your venue's Square location and ready to take in-person card payments.
Your paired readers stay listed in this section, each showing its Name and Code. To add more readers, repeat steps 3–5 with a new name.
Map packages and add-ons to Square items
Mapping links your Rex packages and add-ons to items in your Square catalog, so Square orders and receipts show the right line items instead of a generic charge. Make sure Square is connected and the venue has a Location ID set first — the catalog loads from that location.
Map a package
Open the package
Open the package you want to map.
Pick the Square item
In the integrations list, find Square and pick the matching item from the Items dropdown.
Save the package
Click Save.
Map an add-on
Open the add-on
Open the add-on you want to map.
Edit its package
Open the add-on's Packages tab and edit the package the add-on belongs to.
Pick the Square item
In the Square section, click Get Items List, then choose the matching item from the Item dropdown.
Save
Click Save.
Map every package and add-on so Square orders carry accurate line items. Anything you leave unmapped falls back to the venue's Fallback Item.
How guests pay: full payment vs deposit
How a guest pays through Square depends on the package's deposit setting:
- Full payment (100%) — the guest pays the whole amount at checkout using Square's card form, and the card is charged immediately. This is Square's native payment.
- Deposit (less than 100%) — Rex emails the guest a Square invoice instead. The deposit is due now and the remaining balance is due by the reservation date (or the next day if the reservation is today). The guest can pay the invoice by card, Cash App Pay, or bank transfer (if you've enabled it). Rex marks the reservation paid automatically once the invoice is paid.
The deposit on the Square invoice must be paid within 30 minutes to confirm the reservation. If it isn't paid in time, Rex voids the invoice and cancels the order.
What syncs, and when
| Field | Description |
|---|---|
| Online payments | For full-payment bookings, the guest pays by card (or Cash App Pay) through Square's secure checkout form and is charged immediately. Rex records the payment as a transaction. |
| Square invoices | For deposit bookings (less than 100%), Rex emails a Square invoice with the deposit due now and the balance due by the reservation date. When the guest pays, Rex updates the reservation automatically. |
| In-person payments | Charges taken on a paired handheld are recorded back against the reservation once the guest completes the payment on the device. |
| Customers | Rex matches or creates a Square customer using the guest's email. |
| Catalog | Your packages and add-ons can be mapped to Square catalog items so orders carry the right line items. |
| Refunds | Refunds processed in Square flow back into Rex and update the reservation. |
Disconnecting Square
From the Square card under Settings > Integrations, click Disconnect. You'll be asked whether to keep or clear mapped items:
Keep Mapped Items
Revokes the connection but leaves your location and catalog mappings in place, so reconnecting is faster.
Clear Mapped Items
Also clears the mapped location and item mappings on every venue.
Either way, the connection is revoked account-wide and Square turns off for all venues.
Good to know
- Set the venue's Location ID before creating reader codes — a code is tied to the location that's mapped at the time you create it.
- If payments stop working, re-open Settings > Integrations > Square. If it shows Disconnected, click Connect to re-authorize.
Updated May 30, 2026
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