How Square payments work
When a venue uses Square as its payment processor, Rex communicates directly with the Square API to charge guests, create orders, issue invoices, and process refunds.
Online card payments
When a guest completes a reservation on your booking page, Rex:
Creates or finds a matching customer in your Square account using the guest's email.
Sends a payment request to Square with the reservation amount, the guest's card token, and your venue's Square location ID.
Records the Square payment ID as a transaction in Rex.
The payment note in Square includes the reservation number, guest name, date, venue name, and confirmation number for easy identification.
Square invoices
Rex can create and publish Square invoices for deposit-and-balance payment flows. An invoice is emailed directly to the guest through Square.
Invoices support two structures:
Deposit + Balance
A deposit is due immediately, and the remaining balance is due on a later date.
Full deposit
The entire amount is due on a single date.
Accepted payment methods on invoices include card and Cash App. Bank account payments are available if **Bank Account Enable** is toggled on for the venue.
If an invoice with a "Partially Paid" status needs to be refunded, Rex automatically cancels the invoice first (required by Square) before processing the refund.
Square Terminal payments
Rex supports in-person payments through Square Terminal devices. Staff can initiate a terminal checkout from the host app, which sends the payment request to a paired Square Terminal device. The guest taps or inserts their card at the device to complete the payment.
Terminal devices must be paired to a Square location. Only devices with an "Available" status can accept checkout requests.
Refunds
Refunds are processed back through the original Square payment. Rex sends a refund request to Square with the amount and the original payment ID. Square returns the funds to the guest's original payment method.
Key refund behaviors:
| Field | Description |
|---|---|
| Partial refunds | are supported. Rex calculates the remaining refundable amount by subtracting previous refunds from the total paid. |
| Invoice cancellation | If the reservation has a Square invoice with a "Partially Paid" status, Rex cancels the invoice before issuing the refund. |
| Failed refunds | are recorded as failed transactions in Rex for audit purposes. |
| Rounding | Refund amounts are rounded to the nearest cent using bank rounding to match Square's precision. |
Catalog and order sync
Rex can read your Square catalog to map packages and add-ons to Square items. When a reservation is created, Rex builds a Square order with line items that correspond to the mapped catalog items. This keeps your Square reporting and inventory aligned with reservations.
Catalog items are filtered by location — only items available at the venue's assigned Square location appear during mapping.
Notes
Square tokens refresh automatically before expiration. No manual intervention is needed.
Disconnecting Square at the account level revokes the OAuth token and disables Square on all venues. You can choose to keep or clear catalog item mappings during disconnection.
Cash App and Afterpay availability depend on your Square account's eligibility and country. Enable them per-venue in the Square integration settings.
Updated May 14, 2026
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