Offline Mode was designed to allow you to accept card payments when your Internet service is temporarily unavailable. Provided you’ve enabled Offline Mode in your Square Terminal Settings, it will take effect automatically when your device is not connected to the Internet.
If your Square Terminal is online and all your card transactions appear to be declining, there may be a wider issue affecting payments, which can be confirmed by checking for updates at issquareup.com.
In this instance you can still use Offline Mode, however you will need to navigate to ≡ More > Settings > Hardware > Network and disable Wi-Fi (or unplug your Ethernet cable from the Hub for Square Terminal, if applicable) to force your Square Terminal into Offline Mode.
Once the issue has been stabilised/resolved on issquareup.com, re-enable Wi-Fi (or reconnect your ethernet cable from the Hub for Square Terminal, if applicable) to allow your device access to the Internet and upload your offline transactions.
Note: If you do not force your Square Terminal into Offline Mode by following the steps above, then any transactions you attempt to process will continue to decline and will not be retried once the issue has been stabilised/resolved.
When operating in Offline Mode, there is additional risk with any payments you accept. Square is not responsible for any loss due to declined cards or expired payments taken while offline or for chargebacks. In addition, Square cannot contact any customers on your behalf should a payment be declined or expired when taken in Offline Mode.
Currently, Offline Mode is only available with Square Point of Sale on Square Terminal.
Offline Mode is not yet available on Square Invoices, Square Appointments, Square Invoices, Square for Retail, Square for Restaurants or Square Online. It is also not available on Square Reader, Square Stand or Square Register.