To keep the blank identifiers on (TFN hidden) in a collated document, follow the below steps:
Ensure the blank identifier is enabled before clicking Collate. If you are not sure how to do this, please read the following article: Access HandiSoft (HandiTax): How do I blank out client identifiers (TFN)?
Within HandiTax, go up to Document, Document Manager or press F10 on the keyboard to open Document Manager.
Go to View, Collated Documents and click View to preview the document to ensure the TFN is still hidden.
The document can now be collated, and the blank identifiers will remain on.
NOTE: As the blank identifier option is a HandiTax function, if Document Manager is opened through Practice Manager\HandiSoft, the blank identifiers won't remain hidden. For information on how to collate documents, see this knowledge article.