If the accounts are no longer in use, we can only make them inactive. It'll then show as deleted. Let me walk you through on how to do it:
Go to Accounting on the left panel.
Within the Chart of Accounts tab, locate the account you'd like to remove.
Click the drop-down arrow next to the View register.
Then, select Make inactive. There will be a prompt message appears.
Click Yes to Confirm.
Inactivating an account may change your balance or may cause an adjusting transaction to be created. If you want to use it again, you still have an option to restore it. Here's how to restore the inactive account:
Within the Chart of Accounts tab, click the small gear icon above the Action column.
Place a check in the box for Include inactive.
Locate the account, and click the blue Make active link under Action.
Also, you can check the added articles below for additional reference and guide about handling accounts in QBO: