Can't sigin from excel online sync with my office 365 buisness account

I appreciate you for detailing your concern, Maxcol. Please ensure you've logged in to the appropriate account in your office application. I'm here to help shed some light on this for you.

The reason you're unable to log in is that your personal account is logged in to your office application, not your business account. You can follow these steps to remove your account. Here's how:

1. Open your Office application
2. Sign-out from all Office 365 accounts
3. Quit the Office applications.

You can also check out this article for more common questions about spreadsheets.

If the issue persists, I recommend reaching out to the Microsoft team for further assistance. They are well-equipped to provide detailed guidance on signing into your business account and can offer expert advice on resolving this issue, as it falls under their area of expertise.

Additionally, I've added this article that allows you to create and customize reports in Spreadsheet Sync, giving you the flexibility to organize them or add your style. You can refer to this article for guidance.  Create and edit reports in Spreadsheet Sync QBO Online Advance or Accountant.

Feel free to revisit this thread with any spreadsheet sync questions. We're here to assist you promptly and effectively.