Hi @andrea_larrauri_,
Thank you for posting here in the Community. I can help you void an invoice in QuickBooks Online.
I recommend voiding a transaction to avoid affecting your account balances or reports and having a record of it. You can perform the process by editing the invoice from the Sales section of your account.
Here's how:
- On the left navigation bar, click Sales.
- Go to the Invoices tab.
- Select the invoice.
- Press the More actions drop-down.
- Hit Void.
For more information about transactions you can't void in QuickBooks, I recommend the following article: Void or delete transactions in QuickBooks Online.
Please know that I'm just a post away if you have any other questions regarding voiding sales transactions. Take care.