SuitePOS Offline Mode Explained | SuiteRetail Support

Does SuitePOS work off offline in the event the internet or the NetSuite/Salesforce server is down?

The short answer is yes.  In fact, in addition to speed, this is one of the main advantages of running a separate App. Additionally is you are using the "Square POS" gateway, you can configure it to process credit cards offline (in the integrated Square App). 

When operating in offline mode, bear in mind the following:
  • Transactions will post to a local Fail Queue. On the next sync, an attempt is made to synchronously process the failed transactions (in background).
  • Credit card transactions (using the "Square POS" integration) will post seamlessly as soon as the service is back up and running. 
  • Certain functions such as Shift Opening and Closing, Syncs, Sales Orders, Referenced Returns, Voids, real-time inventory look-up, gift card validation and serial/lot number validation will not work because they require a server-side response.
Notes
Posting of failed transactions are performed synchronously in background to better manage concurrency and avoid tying up the terminal.
Idea
If you have "Shifts" enabled, you can still get in if the internet or the NetSuite (or Salesforce) server is down. You simply "Skip" when the message is displayed.