If your PDF file contains digital signatures, there’s a high chance that the signatures will disappear when you try to join or merge this file with other PDF documents. This is a precautionary measure to ensure that digitally signed documents cannot be altered or that additional pages are not attached to the signed document. However, if you need to keep the digital signatures when merging or attaching, here are 3 ways to do it:

Method 1: Print the File as a PDF

By printing your digitally signed Adobe PDF document as an Adobe PDF file, you can create a new file that retains the signatures when merging or attaching. This is the simplest way to keep digital signatures. To do this, follow these steps:

  1. Open the original PDF file that contains the digital signature.
  2. Click on File > Print. Under Printer Name, select Adobe PDF as shown below and click OK. Adobe will generate a PDF file and prompt you to save it. Save the file using a different filename from the original (for comparison purposes).
  3. Open the newly created PDF file and compare it with the original to ensure they are identical. You can now attach this new file with the digital signatures without any problem.

Method 2: Export the Digitally Signed PDF as an Image

Another way to keep the digital signature on a PDF file to attach is to export the PDF as an image, then convert it back into a PDF file. Here are the steps:

  1. Open the original PDF file that contains the digital signature.
  2. Click on File > Export > Image > JPEG as shown below. Save the image.
  3. Open the folder that contains the newly created exported image file. Right-click on this image and select Combine Supported Files in Acrobat. Follow the prompts and create your new PDF file that will retain the digital signatures when merging or attaching to other PDF documents.

Method 3: Print and Scan the PDF File

This is the old-fashioned method. Simply print your PDF file that contains the digital signature and scan it again for joining or merging. However, this method will reduce the quality of the document.