I just signed an important client contract as a PDF, but anyone can still click and edit or delete my signature field. How do I completely lock or flatten it before emailing the final file?
Honestly the easiest trick is just printing the signed PDF to a new PDF, using the built in print to PDF on your computer. That flattens everything, signature included, so the fields aren’t editable anymore. I do this with plotted drawing sets all the time before sending them out. Just double check the new file looks right before emailing it.
Had the same thing last month with a freelance agreement. If you signed it in Adobe Acrobat (not just Reader), there is usually an option to flatten form fields once signed, which locks everything in place. If you do not have Acrobat, printing the signed PDF to a “Save as PDF” printer on your laptop effectively flattens it too, since it rasterizes the page. Learned this the hard way after a client “accidentally” cleared a signature field once.
@SneakySteel Printing to PDF can flatten the appearance, but it may remove the cryptographic proof of a true digital signature. For an important contract, I’d send the original signed file and use Acrobat’s “Lock document after signing” or certification option, then check the signature panel before emailing.
@SneakySteel Print to PDF works on my old laptop too, but code_pal is right that it kills the signature proof. Not sure if it’s the same on Mac.
I use a certificate-based digital signature with “lock document after signing” enabled, rather than just placing an image signature. In Adobe Acrobat, the signature properties can lock all fields and prevent later edits, and any change after that shows as invalid. For a simpler final copy, I also print to PDF to flatten visible fields, but that is not the same as tamper-evident signing.
The simplest way to flatten a signed contract is to open it in your web browser and select ‘Print to PDF’. This locks your signature completely. Avoid sending editable form files to clients, a lesson I learned the hard way when someone altered one of my bakery invoices. You tagged this with EPUB, but you definitely want to stick to flattened PDFs for this.
I had the same worry with our clinic intake forms. What worked for me was flattening it on PDFcap, which merges the signature into the background so nobody can click or edit it. If you are on Windows, choosing ‘Microsoft Print to PDF’ in your print menu usually does the trick too.
Don’t worry, that happens with signature fields. In Acrobat Pro or another PDF editor, choose Flatten Signatures or Flatten Document on a copy, then reopen it to confirm the signature is no longer selectable. This stops field deletion, though a PDF can never be absolutely tamper-proof. If it is a certificate-based digital signature, flattening may invalidate it, so check first.
@wallabies That check-first habit is what I do with every scanned claim. I flatten a copy, reopen it, and try clicking the signature to confirm nothing is selectable. If it was certificate-signed, I keep the original file as the record and send the flattened copy alongside it.
try printing the signed pdf to a new pdf first like using microsoft print to pdf. that usually flattens the signature so nobody can click and edit it. works for my lease forms anyway. not sure if it’s the same on mac though.
Honestly, the simplest fix I use at work: open it in Acrobat and print to a new PDF, which flattens everything so the signature becomes part of the page. If you want the signature to stay valid as a signature, use Acrobat’s Certify option instead, since flattening by printing technically replaces the signature image. There are also free online flatteners if you don’t have Acrobat, but be careful with client contracts on random sites.