When a user wants to validate an invoice that has been generated, to indicate that it is a formal and authorized payment document, they may do so in Asset Infinity by simply following the steps below:In order to Validate one Invoice at a time, the user can choose to follow the steps below: 

If the user wants to validate a single invoice, go to the purchase menu and then select invoice validation. A new screen will appear, as shown below.

Now, click the edit button to select the record against which you want to validate the invoice. When you click the edit button, a new screen popup appears as shown below.

You can enter the valid invoice number and invoice date here, then click the save button to finish the invoice validation process.