PK4 Tech

An invoice cannot be edited in the following two scenarios:

1. When the invoice is emailed to the customer

• When the invoice is sent using the Send Invoice Email button, the Sent On field is automatically updated with the date and time the email was sent.
  Once this field is updated, the invoice becomes non-editable. When you click Edit Invoice, you will see the message:
  “This invoice was sent on: 07 Nov 2025 17:03. Editing is not allowed.”

2. When the Send Status is set to “Sent”

• If you have manually sent the invoice (for example, by printing and handing it to the customer) and then update the Send Status to Sent, the invoice also becomes non-editable.

To maintain data integrity, please set the “Sent On” field to Read Only in Salesforce. This ensures that users cannot modify the sent date and that invoices remain non-editable once they have been sent.