What happens when I closed the book in QuickBooks? The values of income and expenses disappear or what, hope not.
When you “Close the books” from Accounting Setting* in QBO, it just prevents anyone making changes (or delete) to the file without proper password authorization. It will not wipe out previous years financial data. You will still be able to see prior years financial records which you can’t close in QBO.
* Gear (⚙) icon at the top right corner > Your Company > Account and Settings > Advanced > Accounting > Close the books.