How to Use Digital Signatures with PDF, Excel & Word Documents

In today's digital world, ensuring the authenticity and integrity of documents is critical. Whether you're signing a contract, verifying a financial report, or sharing confidential information, digital signatures provide a secure and legally binding solution. This blog will guide you step-by-step on how to use digital signatures with PDF, Excel, and Word documents.

🛡️ What is a Digital Signature?

A digital signature is a type of electronic signature that uses cryptographic algorithms to ensure:

• Authenticity: Confirms the signer’s identity.

• Integrity: Detects any tampering with the document.

• Non-repudiation: Prevents the signer from denying their involvement.

Unlike scanned images of handwritten signatures, digital signatures are far more secure and legally compliant.

🔐 Prerequisites for Using Digital Signatures

Before you start, ensure you have:

• A digital certificate (from a trusted provider like eSolutions )

• A device with Adobe Acrobat, Microsoft Office (Word/Excel), or other compatible tools

📄 How to Use Digital Signatures in PDFs (Adobe Acrobat)

Step 1: Open the PDF in Adobe Acrobat

Use Adobe Acrobat Reader DC or Adobe Acrobat Pro DC.

Step 2: Select "Fill & Sign"

• Go to Tools > Fill & Sign

• Click "Sign" in the toolbar and choose "Add Digital Signature"

Step 3: Choose Signature Type

• You can either type, draw, or use an image of your signature.

• For digital certificate-based signatures, select “Use a certificate”

Step 4: Sign the Document

• Select your digital certificate.

• Position the signature field and apply the signature.

Step 5: Save the Signed PDF

After signing, the document becomes locked. Any changes will invalidate the signature.

📊 How to Use Digital Signatures in Excel

Step 1: Open the Excel Workbook

Launch your Excel file in Microsoft Excel (2016 or later).

Step 2: Go to the Signature Line

• Navigate to Insert > Text > Signature Line > Microsoft Office Signature Line

Step 3: Set Up the Signature

• Enter signer’s name, title, and email.

• Check options if the signer can add comments.

Step 4: Sign the Document

• Right-click the signature line and choose Sign.

• Choose a digital certificate and apply your signature.

Step 5: Save & Share

• Once signed, the document becomes read-only.

• If any edits are made, the signature will be invalidated.

📝 How to Use Digital Signatures in Word Documents

Step 1: Insert a Signature Line

• Open your Word document.

• Go to Insert > Text > Signature Line

Step 2: Configure Signature Line

• Fill in the details (signer name, title, etc.)

• Click OK to place the signature line in the document.

Step 3: Apply Digital Signature

• Click the signature line and select your digital certificate.

• Add your signature and save the document.

✅ Best Practices for Digital Signatures

1. Use Trusted Certificates: Only use certificates from reliable Certificate Authorities.

2. Keep Certificates Secure: Store your private keys safely and avoid sharing them.

3. Audit Trails: Use signing platforms that offer an audit trail to track who signed and when.

4. Avoid Alterations Post-Signature: Any changes after signing will invalidate the digital signature.

🧰 Tools You Can Use

• Adobe Acrobat Pro DC

• Microsoft Office (2016 or newer)

• DocuSign / HelloSign / SignNow

• GlobalSign / DigiCert / Entrust Certificates

🔚 Final Thoughts

Digital signatures are a vital part of modern document workflows—secure, efficient, and legally recognized. Whether you're signing PDFs, Excel sheets, or Word documents, incorporating digital signatures not only streamlines your operations but also boosts document integrity and trust.

Ready to go paperless and secure? Start using digital signatures today!