Square Terminal

Point of Sale ·5 min read ·Updated July 2026
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you sell with Square and want the register to push the amount to your Square Terminal, or you want to test it in the Square sandbox first.

The POS pushes the amount to your Square Terminal over Square’s cloud. One thing to know before buying hardware: the Square Terminal is the only Square device third-party software can drive – Square Reader, Square Stand and Square Register work exclusively with Square’s own apps.

Requirements

  • A Square account with payments activated (Square operates in the US, Canada, UK, Ireland, France, Spain, Australia and Japan).
  • A Square Terminal device (for live payments; the sandbox needs no hardware at all).
  • A free application in the Square Developer Console – it only exists to give you API credentials; you create it once at developer.squareup.com/apps with your normal Square login.

Live setup

  1. In the Developer Console open your application → Credentials. Flip the environment toggle at the top of the page to Production and copy the Production access token.
  2. In wp-admin go to POS → Card Terminals, set Active provider to Square Terminal, paste the token into Access token, leave the Sandbox checkbox OFF, and save.
  3. Click Create pairing code under Device. A short code appears at the top of the page – it’s valid for 5 minutes.
  4. On the Square Terminal: Sign in → Use a device code and type the code. The Terminal signs in and pairs.
  5. Reload the settings page – the paired Terminal now appears in the device list. Pick it and save.

The register now offers Card – Square Terminal. (You can also enter a device ID or the Terminal’s serial number manually.)

Sandbox setup (no hardware)

  1. In the Developer Console flip the environment toggle to Sandbox and copy the Sandbox access token.
  2. Paste it into Access token, tick the Sandbox checkbox and save.
  3. Under Device, pick one of Square’s simulated devices – Success (payment approved), Buyer cancels, or Timeout – and save.

Sandbox behaviour to be aware of: the simulated device auto-completes the checkout a few seconds after the amount is sent (there is no “simulate card” button – nothing to press), payments are always in USD, and amounts over $25 intentionally stay pending. Keep test sales under $25.

Taking a payment

  1. Ring up the sale and choose Card – Square Terminal.
  2. The amount appears on the Terminal; the register shows Waiting for card….
  3. The buyer taps, inserts or uses Apple Pay / Google Pay. On approval the sale completes, the ticket is issued, and the Square payment ID is stored on the order.

Cancel withdraws the checkout from the Terminal. If the buyer cancels on the device or the request times out, the register shows why.

Refunds

Refund from the POS as usual – the card is refunded automatically through Square and the order gets a note: “Terminal refund sent to Square Terminal (card reversal).” Partial refunds are supported. (Canadian Interac payments are the one exception – Square requires those to be refunded with the card present on the Terminal.)

Troubleshooting

  • Pairing code expired – codes live for 5 minutes; just create a new one.
  • Checkout never reaches the device – the Terminal must be online and signed in with the device code (not into a regular Square account).
  • “NOT_FOUND” or authentication errors – the token and the Sandbox checkbox disagree (production token with Sandbox ticked, or vice versa). Both must point at the same environment.
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