Any one off, upfront or completion invoice can have a credit note applied to it, clearing the balance. Currently it is not possible to add a part credit note, you can only credit note the entire invoice amount.

However it's extremely important not to confuse the credit note feature for sales invoices with the credit note or credit charge features used in Client Accounting.

Firstly it's important you have set up your credit note sequence in your company invoice settings. For more information, see this help article.

A credit note can be applied to a sales invoice either from the property or sale invoices table, or from the main invoices table.

To access a property or sale's invoice table, head to the property page or sale page and click info (top right) > invoices.

To access the main invoices table, click the invoice tab on the left side panel, at the bottom.

From either table, click the three dots on the right of the invoice you want to apply the credit note to and click 'add credit note'.

From here you can enter a customer facing reason for the credit note before adding it. The amount cannot be changed, as the credit note will apply to the entire value of the invoice.

With the credit note applied, you will see a CN flag next to the invoice and see a new invoice created, following the sequence as set up in your invoice settings.

This credit note can then be sent to the client as evidence of the credit note being applied.