As a reseller, you have control over your customers' access to data.
You can set a Company to 4 different statuses in the reseller administration panel:
This is the normal state where everything works, and users can log in.
A softer way to limit access to the company. Users can log in and will not be logged out but cannot access any data
A harder way to limit access to the company account. Users cannot log in and will be logged out.
The company can no longer be seen in any panel, and users cannot log in to it nor access any data on it.