How to check the validity of digital signature

TL;DR

Check a digital signature's validity by verifying signer identity, certificate status, timestamp integrity, and the platform audit trail. Use an eSignature workflow to fill, eSign, validate, and store documents securely. signNow supports certificate validation, robust audit logs, and integrations to automate checks while meeting ESIGN and UETA requirements.

What checking digital signature means

Checking the validity of a digital signature is like confirming a sealed envelope really came from the sender and wasn't opened. It means verifying who signed, that the signing certificate is genuine and unrevoked, that the document hasn't been altered since signing, and that a reliable audit trail exists. In eSignature platforms such as signNow these checks combine signer authentication, certificate checks, timestamps, and secure logs to prove authenticity and integrity.

When validity checks are required

Verifying signature validity matters for legal enforceability, regulatory compliance, and risk reduction. Use signNow when closing remote sales contracts or collecting employee onboarding signatures at scale, and anytime you must prove authenticity for audits, healthcare records, or financial approvals.

Common verification challenges

• Expired or misconfigured signing certificates can make a signature appear invalid even when the signer was genuine at signing time.
• Revoked certificates or compromised private keys require checking certificate revocation lists or OCSP responses to ensure integrity.
• Incomplete signer authentication leaves uncertainty about signer identity when email-based or link-only flows are used without stronger checks.
• Document tampering after signing will break the cryptographic hash and flag the signature as invalid during verification.

Who needs signature validity checks

Organizations that exchange legally binding documents and regulated data depend on reliable signature validation to reduce risk and demonstrate compliance.

• Real estate brokers finalizing leases and closing documents while remote or mobile.
• Healthcare providers capturing patient consents and medical records under HIPAA protections.
• Finance teams approving loan documents, tax forms, and high-value transactions.

User roles concerned with validity

IT Administrator

IT administrators configure authentication methods, manage certificate validation settings, and control integrations so signature verification is automated across systems and aligns with corporate security policies.

Legal Counsel

Legal teams evaluate audit trails, retention policies, and evidence packages to confirm signatures meet ESIGN/UETA standards and can be defended in disputes or regulatory reviews.

Platform security and compliance

Encryption in transit: TLS 1.2/1.3

Encryption at rest: AES-256

Audit and controls: SOC 2 Type II

Health data support: HIPAA (BAA required)

Regulatory compliance: ESIGN and UETA

Quality standard: ISO 27001

Risks of invalid signatures

Contract invalidation: Loss of enforceability

Regulatory fines: Monetary penalties possible

Data breach: Unauthorized disclosure

Reputational harm: Erosion of trust

Litigation costs: Legal defense expenses

Operational delays: Slowed approvals

Real-world verification examples

Two customer scenarios show how signature validation works in practice and the operational benefits of end-to-end eSignature workflows.

Optica Ventures (COO)

Optica Ventures adopted signNow to remove in-person signings and speed closings.

• They used simple templates and mobile signing for investors.
• This ensured consistent identity capture and tamper-evident records for each deal.

Resulting in faster execution and auditable signature evidence for future audits.

Xerox (NetSuite Director)

Xerox integrated signNow with NetSuite to route contracts automatically.

• Integration enforced signer authentication and stored audit trails in a central system.
• The approach reduced manual checks and preserved certificate timestamps and logs.

Leading to repeatable, verifiable signing workflows and clearer compliance records.

Step-by-step validity check

Follow these clear, action-based steps to check a digital signature's validity inside an eSignature workflow using signNow.

• 01
  Upload Document: Open signNow, upload the PDF or Word file you need to validate via the New Document button.
• 02
  Identify Signatures: Open the signed file and locate signature fields and visual indicators of applied digital signatures.
• 03
  Inspect Certificate: Use the signature details panel to view the signing certificate, issuer, and expiration information.
• 04
  Verify Audit Trail: Open the document history to confirm timestamps, IP addresses, and authentication steps recorded by signNow.

How verification works in workflows

Verification is built into each stage of an eSignature workflow: prepare, authenticate, sign, validate, and store with traceability.

• Prepare Document: Add fields, set role order, and require authentication options before sending.
• Authenticate Signer: Enforce email, SMS, or SSO methods to establish signer identity.
• Apply Signature: Signer applies an eSignature which the platform cryptographically binds to the document.
• Validate Post-Sign: Platform checks certificate chain, timestamp, and logs to confirm integrity.

Core signature validation features

Key features you should use when checking signature validity include authentication options, certificate checks, timestamping, and auditable logs inside the eSignature platform.

Signer Authentication

Multiple methods such as email verification, SMS codes, and SSO reduce identity uncertainty before signing.

Certificate Validation

Automatic checks of the signer certificate chain and revocation status confirm cryptographic trustworthiness.

Timestamps

Trusted timestamps preserve the exact signing time to show when a signature was applied relative to certificate validity.

Audit Trail

Immutable logs capture events, IP addresses, and actions to produce an evidentiary record for each document.

Best practices for verification

A concise set of operational practices will help ensure consistent, defensible signature validation across teams and systems.

Standardize authentication across workflows

Define which authentication methods are required for which document types and enforce those settings in signNow templates to reduce variability.

Preserve full audit packages

Save the complete audit trail and evidence package for each signed document in secure storage to support future disputes or audits.

Use timestamp and certificate checks

Routinely validate the signer certificate chain and timestamp to confirm signatures were applied when certificates were valid.

Automate validation on receipt

Use signNow integrations and API calls to automatically validate signatures on intake and flag any verification failures for review.

Time-related checks and triggers

Certain timing rules and triggers help identify when a validity check or additional steps are required during signature processing.

01

Certificate expiry check

Run validation when certificate expiration is within 30 days.

02

Revocation monitoring

Check revocation lists or OCSP responses at receipt.

03

Post-sign retention

Begin retention clock once the final signer completes signing.

04

Periodic revalidation

Schedule automated rechecks for long-term stored documents.

Retention and audit timeframes

Document evidence and signature records require specific retention and audit timelines to meet compliance and litigation readiness.

Short-term evidence:

30 days for immediate dispute window reviews

Standard retention:

7 years for financial and contractual records

Healthcare retention:

Minimum retention per HIPAA and state rules

Regulatory audits:

Keep full evidence for audit duration

Long-term storage:

Archive with integrity checks periodically

Advanced validation capabilities

Beyond core checks, advanced features increase confidence: bulk validation, API evidence export, conditional workflows, and enterprise authentication options.

Bulk Validation

Validate many signed documents at once to scale verification across large batches.

API Evidence Export

Programmatically extract certificate details, timestamps, and audit logs for forensic review.

Conditional Workflows

Trigger extra authentication or manual review when validation flags appear.

SSO and SAML

Use enterprise SSO for stronger signer identity assurance and centralized user control.

Kiosk and onsite signing

Support in-person mobile capture with verification and offline syncing where needed.

Tamper evidence

Cryptographic bindings indicate any post-signing changes to document content.

Managing audit trails effectively

Use these procedural steps to collect, preserve, and use audit data for verifying digital signatures during operational workflows.

01

Enable Logging:

Turn on full audit logs for all signing templates and envelopes.

02

Capture Metadata:

Record IP, timestamp, and authentication method for each signer.

03

Store Evidence:

Save PDF with embedded audit and detached evidence package.

04

Automate Exports:

Use API to export logs to long-term storage systems.

05

Perform Spot Checks:

Randomly validate archived signatures to confirm ongoing integrity.

06

Preserve Chain:

Keep certificate chain and OCSP responses with the record.

FAQs About signature validity

Common questions and solutions for signature verification help teams troubleshoot mismatches, certificate problems, or audit gaps in eSignature workflows.

• Why does a valid signer show invalid?
  If the signing certificate expired or was later revoked, the cryptographic check can show invalid even if the signer was valid at signing time. Check certificate issuing dates, OCSP responses, and whether the platform recorded a trusted timestamp at the moment of signing.
• How do I verify certificate revocation?
  Use built-in OCSP or CRL checks in the eSignature platform to query current revocation status. If automatic checks are unavailable, export the certificate details and query the issuer's status service manually to confirm whether the certificate was revoked.
• What to do when timestamps are missing?
  Missing trusted timestamps can weaken proof of when a signature was applied. If timestamps weren't captured, consult platform logs for server-side event times and consider reissuing signatures with timestamping enabled for future documents.
• How to handle incomplete audit trails?
  If parts of the audit trail are missing, check retention settings and integration export schedules. Reconfigure signNow templates to capture required events and enable redundant exports to secure storage to prevent future gaps.
• Can I validate signatures offline?
  Offline verification requires previously downloaded certificate chains and OCSP responses. Download full evidence packages while online, then perform validation tools offline using the saved artifacts if needed for field or disconnected scenarios.
• Who reviews flagged verifications?
  Establish an internal review team involving legal, compliance, and IT to assess flagged signatures, determine corrective measures, and decide whether re-signing or escalation is required based on risk and document criticality.

Operational timeline for checks

Map out a practical schedule for verification activities across the document lifecycle to ensure timely checks and retain necessary evidence.

01

Pre-send checks

Confirm authentication and template settings before sending documents.

02

Immediate post-sign

Run automatic certificate and hash validation right after final signature.

03

24-hour review

Address any verification flags and notify stakeholders promptly.

04

30-day audit

Perform a follow-up audit on high-value agreements within 30 days.

05

Annual compliance review

Review retention and signature policies annually for regulatory alignment.

06

Event-triggered recheck

Revalidate when legal holds or disputes arise to preserve integrity.

07

Archival revalidation

Periodically recheck stored signatures to ensure continued verifiability.

08

Incident response

Immediately analyze affected records when security incidents occur.

Supported devices and platforms

Access signature verification features via web, mobile apps, and API endpoints to suit desktop and field workflows.

• Web browsers: Modern Chrome, Edge, Safari
• Mobile apps: iOS and Android
• APIs: RESTful API access

Recommended workflow settings

A typical signNow setup to ensure reliable signature validity combines authentication, retention, and validation defaults to create repeatable, auditable workflows.

Setting Name	Default Configuration
Reminder Frequency	48 hours
Authentication Method	Email + SMS
Audit Trail Retention	7 years
Bulk Send Capabilities	Enabled
Certificate Validation Mode	Auto-check

Quick feature comparison

Comparison of core validation-related capabilities across leading eSignature providers, with signNow listed first as Recommended.

Feature	signNow (Recommended)	DocuSign	Adobe Sign
Certificate validation	yes, auto
Bulk validation			varies
API evidence export
Envelope limits	no cap	100/year	no cap

Pricing and feature snapshot

Pricing and feature data current as of May 2026, showing starting prices, trial availability, bulk send, audit trail, HIPAA support, and envelope limits.

	signNow	DocuSign	Adobe Sign	PandaDoc	HelloSign
Starting Price	$8/user/mo	$8/user/mo	$13/user/mo	$19/user/mo	$15/user/mo
Free Trial	7-day free trial, no card	Varies by plan	Varies by plan	Varies by plan	Varies by plan
Bulk Send	Yes, Business Premium	Limited	Yes, add-ons	Yes	Yes
Audit Trail	Yes, full audit	Yes	Yes	Yes	Yes
HIPAA Compliant	Yes, BAA required	Contact vendor	Contact vendor	Contact vendor	Contact vendor
Envelope Cap	No envelope cap	100 envelopes/year	No cap	No cap	No cap