What steps do we need to take to resolve the quota limit isue?

Have a user who uses your service. Their web page states that Jot Form has reached quota. What steps do we have to take to resolve this?

The user was on a Storage paid plan under which the number of forms in their account is limited to five. The total number had reached five and hence the message of over quota.

Either the user needs to delete any form that is not being used or they have to upgrade the paid plan - How-to-Upgrade-My-Account  

The guide below will give you an idea on the limits allowed under each plan.

https://www.jotform.com/help/408-Understanding-Your-Account-Usage-and-Limits