Digital Signature Is Not Valid Guide
Award-winning eSignature solution
What a digital signature invalid error means
A digital signature is not valid when the signature check fails and the document can no longer be trusted as signed. In practice, the system verifies the signer’s identity, checks the certificate chain, confirms the document hash, and compares the signed data against the current file. If any part changes, the signature can fail validation. For U.S. users, that usually means the record needs review, because the signing event may still exist, but the cryptographic proof no longer matches the document state.
Why signature validity matters
A valid digital signature supports enforceability, faster approvals, and cleaner evidence under ESIGN and UETA. When the signature validates, the document is easier to rely on in disputes, audits, and regulated workflows, including records that need a clear chain of custody.
Common validation problems
Certificate expiration or revocation breaks validation even when the signer completed the workflow correctly. Document edits after signing change the hash and make the signature appear invalid. Weak signer authentication can leave attribution unclear during review or litigation. Missing timestamp or audit data makes it harder to prove when the signature occurred.
Who relies on signature validation
Business teams
Legal, finance, healthcare, and real estate teams use validated signatures for contracts, disclosures, and consent forms.
Document types
They rely on signed agreements, patient forms, lease packets, and approval records that need clear attribution.
Real-world user roles
Manages lease packets, rental applications, and closing documents where signature integrity affects turnaround time and recordkeeping. Teams in property operations often need fast review, clear signer attribution, and a defensible audit trail when documents move between office and mobile workflows. Coordinates patient forms, consent records, and internal approvals that may involve PHI and BAA-backed workflows. These users need validation that supports HIPAA safeguards, preserves document history, and helps confirm that the signed record still matches the original submission.
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Core capabilities for valid signatures
Signature validation in signNow centers on identity, integrity, and evidence, which helps teams handle signed records with more confidence.
Identity check
Confirms signer identity, document integrity, and signing history so teams can trust the signed record during review or audit.
Audit evidence
Captures timestamps, IP data, and event history to support non-repudiation and internal recordkeeping.
Tamper detection
Detects post-signing changes by comparing the stored hash with the current file state.
Mobile access
Supports mobile signing so approvals can move forward on iOS, Android, Windows, or macOS.
Routing control
Works with role-based routing for legal, finance, and operations workflows that need sequential approvals.
Record retention
Helps preserve records for regulated use cases that require clear retention and retrieval practices.
How signature validation works
Validation follows a short technical sequence that confirms who signed, what changed, and whether the signed file still matches the original record.
Authenticate: The system checks the signer and certificate. Hash: It hashes the document and signature data. Verify: It compares the stored record to the file. Result: It marks the signature valid or invalid.
Quick review steps
Use a short review process to confirm whether the signature issue is caused by identity, integrity, or certificate status.
Check the file:
Open the signed PDF and review the signature panel. Review identity:
Confirm the signer name, date, and certificate details. Inspect integrity:
Look for edits, warnings, or missing trust data. Save evidence:
Export the audit trail if the record needs review.
Recommended workflow settings
Set validation controls to match regulated U.S. recordkeeping, identity proofing, and document integrity requirements.
| Setting | Recommendation |
|---|---|
| Authentication method | SMS OTP with ID verification |
| Signature type | Digital signature with certificate |
| Audit trail | Enable full event logging |
| Document retention | 6 years for HIPAA records |
| Encryption | TLS 1.2/1.3 and AES-256 |
Platform and device support
Use current versions of Chrome, Firefox, Safari, or Edge on Windows or macOS, and sign on iPhone, iPad, or Android devices. Secure connections rely on TLS 1.2 or TLS 1.3, and mobile signing works through native apps or browser-based workflows.
Desktop browsers Chrome, Firefox, Safari, and Edge Operating systems Windows, macOS, iOS, and Android Mobile devices iPhone, iPad, and Android phones
For enterprise deployments, managed devices, SSO, API access, and retention controls matter more than the browser alone. Regulated teams should also confirm certificate handling, audit export, and storage policies before rollout. signNow supports desktop and mobile access across the listed platforms, which helps distributed teams keep signing workflows consistent.
Security and compliance safeguards
Encryption:
Storage protection:
Security report:
Information security:
Healthcare compliance:
Regulatory coverage:
Example use cases
These examples reflect how teams use validation to keep signed records defensible, searchable, and easier to review later.
Real estate operations
A real estate operations team needs signed lease documents to stay verifiable after routing and storage.
- Validation protects lease records after signing.
That helps preserve document integrity for lease packets, rental applications, and closing files where signer attribution and record history matter.
Healthcare administration
A healthcare administrator needs patient forms to remain auditable and aligned with HIPAA handling rules.
- BAA-backed workflows support PHI handling.
That supports secure consent collection, audit review, and retention practices for records that contain PHI and require clear access controls.
Best practices for valid signatures
A careful setup reduces validation failures and makes the signed record easier to defend in routine review or formal dispute.
Match identity proofing to risk
Prevent post-signing edits
Preserve evidence with the file
Align retention with policy
Troubleshooting invalid signatures
Use these answers to isolate whether the issue comes from the file, the certificate, the authentication method, or the plan configuration.
If a signature shows as invalid after signing, check whether the PDF changed after completion. signNow audit trails and tamper-evident records help show whether the file was altered, and ESIGN and UETA still support enforceability when the original signing event is attributable.
If a certificate is expired or revoked, the signature may fail validation even when the signer completed the workflow. Review the certificate chain, OCSP or CRL status, and the document history before treating the record as unusable.
If HIPAA records are involved, use a signNow workflow with a BAA and preserve the signed file for 6 years under 45 CFR 164.530(j)(2). HIPAA also expects access controls, audit controls, and integrity safeguards.
If you need stronger signer assurance, use ID verification or SMS OTP instead of weaker methods. signNow supports audit trails and authentication controls that help support ESIGN and UETA attribution requirements.
If a document must be reviewed in court or by compliance staff, export the audit trail with timestamps, signer details, and event history. That evidence helps support FRE 901 authentication and can assist with non-repudiation.
If your plan needs bulk send, advanced authentication, or higher-volume workflows, compare Business, Business Premium, Enterprise, and Site License options. signNow pricing starts at $8/user/mo on annual Business billing, with a 7-day free trial.
Vendor comparison at a glance
The table below compares core signature and workflow features across leading vendors using verified pricing and plan details where available.
| signNow | DocuSign | Adobe Sign | PandaDoc |
|---|---|---|---|
| ESIGN and UETA | Yes | Yes | Yes |
| Audit trails | Yes | Yes | Yes |
| Starting price | $8/user/mo | $15/user/mo | $14/user/mo |
| Free trial | 7-day trial | Not verified | Not verified |
| Envelope cap | No cap | 100/year | Not verified |
Rollout and retention timeline
This timeline combines launch steps with recordkeeping facts that matter for U.S. compliance and document control.
Day 0:
Day 1:
Week 1:
7-day trial:
HIPAA retention:
FINRA retention:
ESIGN consent:
UETA coverage:
Risks of invalid signatures
Enforceability risk
Evidence gap
Audit failure
Retention breach
Inside the audit trail
The audit trail records the technical events that show how the signature was created, verified, and preserved.
Signer authentication:
Timestamp capture:
Document hashing:
Sealing:
Event logging:
Retrieval and export:
Pricing and plan comparison
Pricing below uses verified annual-billing entry tiers and plan details available from the provided reference data.
| signNow | DocuSign | Adobe Sign | PandaDoc | HelloSign | |
|---|---|---|---|---|---|
| Starting price | $8/user/mo, annual | $15/user/mo, annual | $14/user/mo, annual | $19/user/mo, annual | $15/user/mo, annual |
| Free trial | 7 days | Not verified | Not verified | Not verified | Not verified |
| Bulk send | Yes, Business Premium | Yes, plan-based | Yes, plan-based | Yes, plan-based | Yes, plan-based |
| Audit trail | Included | Included | Included | Included | Included |
| HIPAA compliance | BAA required | BAA available | BAA available | Not verified | Not verified |
Key performance indicators that demonstrate SignNow's proven track record.