If you send an invoice and then realize you need to change something like the amount due or the description, you will need to delete the original invoice and send a new one. This can only be accomplished if the invoice sent has not yet been paid.
Go to My Dashboard and under "Project" select the project you are referring to. You can also click on the invoice sent under "Activity" to access the same project screen. From there, find the invoice you want to change and select Cancel Invoice.
If you’re sure this is the invoice you want to delete, select Yes on the following confirmation screen.
Then, once the invoice is deleted, you can simply send a new invoice with the proper information by selecting Create New Invoice.