Hello there, @richardsmachine.
A user may have changed your company information. To check this, you can go to the Audit log to see who made the changes.
Here's how:
- Click the Gear icon on the upper right.
- From the Tools section, select Audit log.
- Filter it to All Users, and tick the Show All Events to see the activities.
- Select Apply.
Once done, you'll see this output.
To learn more about how to use the audit log, you can check this article: Use the audit log in QuickBooks Online.
You can also use the audit log to re-enter deleted transactions in the future.
If you have other concerns, Keep me posted. I'm here to help anytime. Have a nice day ahead!