Whenever creating a sales invoice, you have an option to save or approve it before sending it to your customer.
- If it's saved, it will be kept as a draft and you are able to modify it, but you can't send it to the customer before approving it.
- If its Approved, Invoice will be locked against any modifications and can be sent to your customer.
It is still possible to edit an approved sales invoice, but it requires canceling the approval and requires "Accountant" or "Administrator" user permissions.
To cancel approval from sales invoice
- Go to Sales
- Find and open the invoice you are willing to modify
- Click Cancel confirmation
After the canceling, the adjustments to the invoice can be done by the user, who initially created the invoice or by the user with administrator privileges.