Hi there, claudiaSp. Here's some information on deleting, making inactive, and merging fund accounts in QuickBooks Online (QBO).
Undeposited Funds is a permanent account in your chart of accounts. Therefore, it can't be deleted or made inactive. However, we can merge other similar accounts with Undeposited Funds to add their balances to the default account. This will help keep your records organized and accurate.
Otherwise, the accidentally created undeposited funds will be made inactive.
Here's how:
Go to the Gear icon, and select Chart of accounts.
Select the created Undeposited Funds on the Chart of accounts page.
Click the dropdown ▼, and select Make inactive.
When the message prompts, click the Yes, make inactive message.
The screenshot is attached for visual reference.
Your account will become inactive, but all the recorded transactions will still be available.