Generally, those states in which you did business
Taxpayers must file in the states in which they have a taxable presence. "Nexus" is the term generally used to indicate this connection. Nexus is created for income tax purposes if an entity derives income from sources within the state, owns or leases property in the state, or employs personnel in activities that exceed "mere solicitation" within the state.
Although the requirements vary from state to state, please indicate all jurisdictions in which you believe you may have nexus. If you find that you selected states where there is no filing obligation after you have connected with your Pro, you or your Pro may reach out to Taxfyle through the help chat to have the details and price of your engagement corrected.