Our corporation is newly formed and has three founders. I'm the only one in the States, so I've opened a mailbox to handle all correspondence not handled by our DE registered agent. As such, I've been told I would personally count as a "nexus" in my home state so I might need to register the business at either the state, county and/or city level. We do not have a storefront, only a mailbox. We're entirely web based SaaS and cover services across the globe. My home is in Charlotte, North Carolina. NC does not have a sales tax for SaaS's, so I don't think we need to register for a sales tax ID. No clients visit my home. There are no employees in the state other than myself, and even then, I'm an officer and not on payroll at this stage in the startup process. Aside from that, what specifically, if anything, am I registering in NC/Mecklenburg/Charlotte to make sure we stay legal?