The Sent On field for an invoice is updated automatically when the invoice is emailed to the customer using the “Send Invoice Email” button.
If you are manually sending the invoice by taking a printout this field will not be updated automatically. In such cases, you can manually enter the details by following the steps below:
Go to the TT Invoices tab.
Search for and click the Invoice Number to open the invoice view page.
Update the Sent On field with the appropriate date and time, then save the record.
Once the Sent On field is updated, the invoice will become non-editable when you click the Edit Invoice button.