Electronic signatures

Chaindoc lets you add legally binding e-signatures to any document, with blockchain verification baked in. This page covers the three signature types, compliance details, and how the signing workflow actually works.

Every signature gets recorded on the blockchain, which creates a tamper-proof record that holds up in court. That's on top of the standard audit trail (timestamps, IP addresses, auth method). If you're new to Chaindoc, the quick start guide walks you through sending your first signature request.

Signature types

Chaindoc supports three levels of e-signature. Most business contracts work fine with simple signatures. Regulated industries usually need advanced or qualified.

Simple electronic signature (SES)

The default for everyday documents. Signers click to sign after email verification. There's no extra authentication step, so the process is fast.

• Click-to-sign with email verification
• Works well for NDAs, internal approvals, and informal agreements
• Audit trail with timestamp and IP address
• Signing takes under a minute for most documents

Advanced electronic signature (AES)

Adds multi-factor authentication before signing. The signer proves their identity via SMS, authenticator app, or email code. This is the right choice for contracts, employment agreements, and vendor agreements where you need stronger proof of who signed.

• Multi-factor authentication (SMS, authenticator, or email)
• Identity verification before the signer can access the document
• Full audit trail including authentication details
• Blockchain-verified certificate of completion

Qualified electronic signature (QES)

The highest level. QES has the same legal weight as a handwritten signature in the EU under eIDAS. It requires government-issued ID verification and certificates from a trusted authority. If you're in legal, financial services, or healthcare, this is probably what your compliance team will ask for.

• Certified by trusted certificate authorities
• ID verification with government-issued documents
• Compliant with eIDAS, the ESIGN Act, and UETA
• HSM-protected certificates
• Immutable blockchain proof of signature

Legal compliance

Chaindoc signatures comply with the major e-signature regulations. Here's what's covered and how it works in practice.

Supported regulations

• eIDAS — Electronic Identification and Trust Services (European Union)
• ESIGN Act — Electronic Signatures in Global and National Commerce (United States)
• UETA — Uniform Electronic Transactions Act (United States, adopted in 47 states)
• PIPEDA — Personal Information Protection and Electronic Documents Act (Canada)
• Electronic Transactions Act (Australia)
• Information Technology Act (India)

What makes a signature legally valid

Chaindoc handles these requirements automatically, but it's worth knowing what's happening behind the scenes:

• Signers must explicitly consent to sign (no auto-signing)
• Each signature is cryptographically tied to the document
• Documents are stored with tamper-proof integrity checks
• Signer identity is verified at the level you configure
• Full audit trail: timestamps, IP addresses, auth method, device info
• Blockchain hash provides independent, permanent proof

For a deeper look at encryption and access controls, see the security best practices guide.

Signing workflow

Creating a signature request

You can create requests through the web interface or via the API. The steps are the same either way:

1. Upload your document (PDF, Word, or image)
2. Add signers with their email addresses
3. Pick a signing order (sequential, parallel, or hybrid)
4. Place signature fields on the document
5. Choose the signature type and authentication level
6. Set a deadline and optional custom message
7. Send the request

If you're doing this via code, the API docs have the full endpoint reference. The SDK method is `chaindoc.signatures.createRequest()`.

Signature field types

You can add different field types to your documents. Not every document needs all of these, but they're available:

• Signature — the main e-signature field
• Initials — for initialing individual pages or clauses
• Date signed — auto-filled with the signing timestamp
• Text field — for names, titles, or any custom text
• Checkbox — for consent or acknowledgment
• Dropdown and radio buttons — for selecting from options

Signing order options

• Sequential — signers get the document one at a time, in the order you set
• Parallel — everyone gets it at once and can sign independently
• Hybrid — mix sequential and parallel groups (e.g., both clients sign in parallel, then the manager signs last)
• Conditional — the next signer depends on what the previous one did

What signers see

Understanding the signer's experience matters if you want high completion rates. Here's the flow from their perspective.

The signing flow

How signers create their signature

Signers can pick whichever method feels most natural:

• Type their name and pick a font style
• Draw with a mouse, trackpad, or touchscreen
• Upload an image of their handwritten signature
• Use a saved signature from a previous signing session

Blockchain verification

This is what separates Chaindoc from standard e-signature tools. Every signed document gets a hash written to the blockchain, creating a permanent, independent proof that the document hasn't been modified since signing.

What gets recorded

• A cryptographic hash of the signed document
• Unique transaction ID for each signature event
• Block number and timestamp on the blockchain network
• The record is permanent and can't be deleted by anyone, including Chaindoc

How to verify a document

Anyone can verify a signed document, even without a Chaindoc account:

1. Go to the verification portal at verify.chaindoc.com
2. Upload the signed document or enter the verification code
3. The system calculates the document's hash and checks it against the blockchain
4. You'll see the result: document integrity status, signature dates, and signer details
5. Download a verification certificate if you need one for your records

Audit trail and certificate

Every signature generates a detailed audit trail and a certificate of completion. The audit trail is what you'd show a court or auditor if someone disputes a signature.

What the audit trail captures

• When the document was sent and by whom
• Email delivery and open timestamps per recipient
• When each signer viewed the document
• Authentication method and success/failure logs
• Signature timestamps (millisecond precision)
• IP addresses and device information
• Geolocation data (if enabled)
• Blockchain transaction ID and block number

Certificate of completion

Generated automatically when all parties have signed. It bundles everything into one document:

• Document title and unique ID
• All parties, their roles, and their actions
• Complete event timeline
• Signature images and typed names
• Authentication methods used
• Blockchain verification data
• QR code for instant verification

Advanced features

In-person signing

Sometimes you need to collect signatures face-to-face. Chaindoc's host mode lets multiple people sign on the same device, with separate email verification for each signer. Useful for events, conferences, or office walk-ins.

Bulk send

Need to send the same document to dozens (or hundreds) of people? Upload a CSV with recipient info, use merge fields for personalization, and track each one individually. Think onboarding packets, policy acknowledgments, or annual renewals.

Reminders and notifications

Automatic reminders go out every 3 days by default (you can change the interval). You'll also get notifications when documents are viewed, signed, or declined. Set up webhooks if you want these events pushed to your app in real time.

Decline and void

Signers can decline a request and provide a reason. You get notified immediately. On your end, you can void a document at any point before completion. Both actions are logged in the audit trail and all parties get notified.

Best practices

Preparing your documents

A few things that save time and reduce signing friction:

• Use clear document titles. "Q4 2025 Consulting Agreement" is better than "Contract_v3_final_FINAL.pdf".
• Compress large PDFs before uploading. The max is 50MB, but smaller files load faster for signers.
• Place signature fields where signers would naturally expect them.
• Label fields clearly: "Client Signature", "Manager Approval", not just "Signature 1".
• Test the signing flow yourself before sending it to real recipients. You'll catch layout issues early.

Security tips

Match the signature type to the document's importance. Don't over-engineer it, but don't skip authentication for contracts that matter.

• Use AES or QES for legal and financial documents
• Enable MFA for anything where the signer's identity is critical
• Set reasonable deadlines (7-30 days for most contracts)
• Keep signed documents backed up and accessible
• For high-value contracts, verify the blockchain record after signing

Troubleshooting

Signer didn't get the email

Check their spam/junk folder first. If it's not there, verify the email address is correct and resend the request. Some corporate email filters block signing links, so you may need to whitelist chaindoc.io.

Signing link expired

You can extend the deadline from your dashboard and resend. The signer gets a fresh link.

Can't draw signature on mobile

Make sure the browser allows touch input. If it still doesn't work, the signer can switch to a typed signature instead. All signature methods have the same legal validity.

For API-specific issues, check the API documentation. For webhook delivery problems, there's a retry and debugging guide in the webhooks docs. If you're setting up team roles and permissions, that's covered in the team management section.