Once an invoice is created, it cannot be modified. If you need to make changes, you must cancel the invoice and issue a new one. Invoices that have been fully or partially paid cannot be canceled.
If cancel is an option, you will be able to click Cancel Invoice in the upper right corner. If you are in the mobile app or in a web browser on a mobile device, you will nee to click the two lines in the upper right corner for a dropdown menu to find it. If it is greyed out, the invoice cannot be canceled.
The invoice cancellation message is optional, but it can be very helpful to record the reason in case you have to look back at this later and you don't remember the details. Your customer will be able to see this message.
The link to the invoice will still work for your customer, but the status will update to Canceled. Sending a notification to your customer is optional. If the email could be confusing or upsetting, you can select Don't Send Email.
The invoice will remain in your list of invoices associated with the project and customer, but the amount due is added back to the amount left to invoice on the project.