One of my company files is completely gone from quickbooks online. When I tab down to switch companies from the top of the screen, it is not there anymore. Need it back!!

Hi there, buckinhorses-yah.

When doing a switch, check if the company is on your list of Canceled Companies. These are QBO companies that have expired.

Another reason is you were removed as a user of that QBO Company that's why you're no longer seeing it. You can ask the primary admin to add your back.

Feel free to go back to this thread if you have other questions in mind.