Fix Digital Signature Field Missing in Acrobat Reader Mobile
Question details
Users are unable to see or interact with a required digital signature field in the mobile version of Acrobat Reader, preventing them from signing the document.
- Product
- Acrobat Reader Mobile
- Device & OS
- Mobile
- Scenario
- Attempting to fill out and submit a secure PDF form containing standard form controls, a submit button, and a required signature block on a mobile device.
- Observed behavior
- Other form controls and the submit button function properly, but the digital signature field is completely invisible or unclickable.
Verify whether the PDF document requires a standard electronic signature (a drawn image) or a certificate-based digital signature, as mobile applications have strict limitations on handling cryptographic certificates.
Open and Sign the PDF Using Desktop PDF Software
Since certificate-based digital signatures are not supported on the mobile app, you must open the document on a desktop computer to view the field and sign.
Acrobat Reader Mobile and most other native mobile PDF viewers do not support advanced, certificate-based digital signature fields due to mobile operating system security restrictions regarding certificate storage. To resolve this, the file must be processed in a desktop environment.
Send the PDF file from your mobile device to a Windows or Mac computer via email, cloud storage, or a direct file transfer method.
Launch a desktop PDF application, such as Acrobat Reader Desktop or WPS Office PC, and open the transferred PDF file.
Locate the signature field, which will now display correctly. Click the field to apply your digital certificate or draw your signature as required.
Save the signed document locally and use the form's submit button or attach it manually in an email to complete the process.
Request an Electronic Signature Field Instead
If you must sign the document on your mobile device, ask the document creator to modify the signature requirement.
Easily View and Sign PDFs with WPS Office PC
Bypass mobile app limitations by using WPS Office on your computer to open, fill out, and securely sign your PDF forms with full compatibility.
- 1. Install WPS Office: Download and install the free WPS Office suite on your Windows or Mac desktop computer.
- 2. Open your PDF file: Launch WPS PDF and open the document containing the required signature field.
- 3. Access signature tools: Navigate to the 'Fill & Sign' or 'Protect' tab on the top ribbon menu to access signing options.
- 4. Sign the document: Click directly on the designated signature field to securely insert your electronic or digital signature.
- 5. Export and send: Save your digitally signed PDF document and forward it to the intended recipient.
Frequently Asked Questions
Why does my signature field show up on a computer but not on my phone?
Mobile PDF viewer applications generally do not support certificate-based digital signature fields due to limitations in how mobile operating systems handle cryptographic certificates. They require full desktop software to authenticate and display correctly.
Is there any mobile app that supports certificate-based digital signatures?
Most native mobile PDF readers lack full digital certificate support. While you can easily draw an electronic signature on most mobile PDF apps, applying a cryptographic digital signature usually requires an enterprise desktop application or a specialized cloud-based service.
How can I sign this PDF if I don't have access to a computer?
You can contact the document issuer and request they send the document via a web-based e-signature platform (like Adobe Sign or DocuSign). These services work directly in mobile web browsers without relying on native PDF fields.
What is the difference between an electronic signature and a digital signature in PDFs?
An electronic signature is essentially an image or drawing of your signature placed on the page, which works easily on mobile. A digital signature uses a cryptographic certificate to verify your identity and ensure the document has not been altered after signing, which typically requires a PC.
