Adding a headed paper background to an existing invoice PDF but preventing any additional editing

[Scott5E1E]

Hi,

I have a customer who requires a specific header on their invoices and for it to be emailed to them.

Our current invoices are generated as a PDF from our business software, we then print on to headed paper and post out.  For this customer, additional steps are that we scan the printed document and email it out. 

We'd like to remove the print to headed paper stage to save resources.

I understand that we can use Acrobat to add a background (headed paper) but there are concerns that this gives employees the ability to edit invoices further than just the background i.e. they spot a mistake, edit the pdf to correct it but not the business software.  Therefore our invoice sent doesn't match the system record.

Is there a simple way I can perform this background addition whilst maintaining security of the document content?

Thanks Scott

[try67]

You can digitally sign the file, after adding the header. Any changes to it after that point will invalidate the signature.

[Scott5E1E]

Thanks for responding @try67 unfortunately it still means that the document could have additional edits made at the same time as the header is applied and therefore doesn't meet our accountants requirements.

[try67]

Yes, the document can atill be edited, but you will be able to prove that it was edited. This is in fact the only way you can do that, unless you spend a small fortune on DRM protection. The choice is yours.

[Scott5E1E]

Understood, thank you