I can share some information on how to delete an account from your chart of accounts, @Chaya_Maine. 

Can you tell me about the account that you're trying to delete? Also, the error you've encountered when trying to delete one? That'll help us provide the right solution to this concern. 

In QuickBooks Online (QBO), there are product features that rely on default accounts. Thus, you can’t delete them. However, some accounts require extra steps before deleting them. 

If you're trying to delete an account linked to a recurring transaction, you'll have to unlink any recurring transaction templates that use it.

First, run a Recurring Transactions Template list. Once done, you can now delete an account from your chart of accounts. You can check this article for more information: Review your recurring transactions in QuickBooks Online. 

You can check this article for more information: Delete an account on your chart of accounts in QuickBooks Online. 

Keep me posted if there's anything that you need with your account or if you have follow-up questions with your chart of accounts. I'm always here ready to help.