Per the IRS Closing a Business webpage:
Closing your business can be a difficult and challenging task. The IRS has resources that can help you navigate this. On this page, you’ll find the steps you’ll need to take to close your business from a federal tax perspective regardless of your business type and information to help you take care of your employees. Whether a sole proprietorship, partnership or corporation, information on this page will help you understand what to file and how to report income you receive and expenses you incur before closure. Remember to check your state responsibilities when closing a business.
On this page:
On the return for the tax year in which your business ceases to exist, click the Checkbox next to Final Return. If there are Schedules K-1, do the same for the Schedules K-1.
Note. Schedules C (Form 1040), E (Form 1040), and F (Form 1040) do not have check boxes to indicate a Final Return.
Note that any link in the information above is updated each year automatically and will take you to the most recent version of the webpage or document at the time it is accessed.