How to add stamp to PDF? Stamping PDF files based on date/time with different alignment using PDF batch stamp tool. Using bates stamp software you will increase the page numbers, add stamp in PDF or create stamp in PDF, add watermark in PDF document, insert date/time, add case codes, stamp, logo, text stamp, confidential etc. Trial version of PDF batch stamp is available at free of cost. Get full version of PDF Batch stamp tool at just $129.