Your employer might have ended your split billing agreement - for instance when you have left the company. A valid question then remains what happens to your Smappee Smart Charging Station.
When Split Billing was activated for your charging station the configuration has been changed to the payment method Swipe & Charge (Split Billing). This allowed you to scan your Smappee Smart Charge Card and as such reimburse any of your sessions via the split billing agreement. Now that the agreement has ended your Smappee Smart Charge Card will be disabled and therefore swiping the card will not allow you to start your session.
The configuration of the charging station will not have changed after the split billing agreement has ended. Your partner, or someone else from the same household, might be using split billing as well on the same charging station and as such changing the configuration would not allow others to charge.
If the charging station is owned by the employee, then he or she can change the configuration to disable Swipe & Charge (Split Billing) and use the charging station in Plug & Charge mode. It is up to your employer to decide what happens with the charging station in case it was installed and owned by the employer. In many cases this has been documented in your company's car policy. You can find more on changing the different session activation methods here.