One-time voice enrollment binds a verified principal ID to every future authorization — agents and humans share the same attribution model.
EnterpriseVoice authorization
Authorize by voice. Prove it in the audit trail.
Voice signing adds enrollment, step-up authorization, and hands-free ceremonies to the same envelope infrastructure as tap-to-sign. Signers confirm intent by voice — tuned for Southeast Asian accents and code-switching — and every authorization event lands in the append-only audit log alongside consent and signature metadata.
Last updated: July 4, 2026
Configure voice step-up per envelope, template, or dollar threshold. Tap-to-sign remains available where policy does not require voice.
Delegation scopes tie agent credentials to a voice-verified principal — explicit limits, short-lived tokens, instant revocation.
Capabilities
Authorization by voice, evidence by design.
Voice signing is not a separate product — it is a step-up authorization method on the same envelope infrastructure you already use. Enrollment, ceremonies, delegation, and audit events share one state machine with tap-to-sign.
Voice enrollment
Signers enroll once with a spoken passphrase. SumoSign returns a verified principal ID that binds every future voice authorization to a real person.
Step-up authorization
Voice approval plugs into the same envelope state machine as tap-to-sign. A second, stronger checkpoint for high-trust contracts — consent, signature, and voice confirmation in one audit trail.
Voice-guided ceremonies
Hands-free signing for field teams, accessibility requirements, and signers who need to complete a contract without touching a screen. The ceremony walks them through each field by voice.
Delegation scopes
A human principal defines what an agent may do on their behalf — sign contracts up to $10K, send NDAs only, route but not sign. Policy is stored, enforced, and attributed in the audit log.
Short-lived credentials
Agent credentials expire when the task ends or the principal revokes them. Zero standing privileges — nothing idle for an attacker to steal.
Evidence-grade audit trail
Every voice authorization is logged: principal ID, scope, timestamp, envelope, and IP. Structured for counsel under Singapore ETA and Australia's Electronic Transactions Act.
Languages
Built for how Southeast Asia actually speaks.
Generic speech models still stumble on Singlish, Tamil-English mixes, and rapid code-switching. SumoSign voice enrollment and ceremonies are tuned for the accents and patterns your signers use every day — not a US-centric read-aloud script.
English (Singapore)Singlish & code-switchingBahasa MelayuTamilVietnameseMandarin-in-English mix
1. Signer opens enrollment link (one-time)
2. Consent to voice biometric processing (PDPA)
3. Speak passphrase × 3 for liveness
4. Principal ID issued → bound to org + email
5. Future authorizations verify against principal
// Agent delegation (optional)
POST /v1/delegations
{
"principalId": "prin_8k2m…",
"agentId": "agt_4f9a…",
"scope": "sign_envelopes",
"maxValueUsd": 10000,
"expiresAt": "2026-12-31T23:59:59Z"
}Workflow
Enroll once. Authorize on every envelope that matters.
The autonomy dial moves in stages: agents prepare and send, humans sign. Voice adds a stronger human gate — explicit, attributable, and recorded in the same audit trail as every other envelope event.
01
Enroll
The signer speaks a passphrase once. SumoSign verifies voice against the enrolled principal and stores a cryptographic binding — not a recording of their voice on every contract.
02
Prepare
Your team or agent prepares the envelope as usual: document, recipients, routing, fields. Voice authorization is configured per envelope or per organization policy.
03
Authorize
At signing time, the recipient confirms intent by voice — a spoken phrase tied to the specific envelope. Tap-to-sign still works; voice is an additional affirmative act where policy requires it.
04
Prove
The completion certificate and audit JSON include voice authorization events alongside consent capture, document hash, and signature metadata. One evidence bundle for procurement and legal review.
Use cases
When voice beats tap-to-sign.
Not every envelope needs voice authorization. Configure it per template, per dollar threshold, or per organization — and keep tap-to-sign for everything else.
High-value contracts
Require voice step-up on MSAs, investment agreements, or any envelope above a dollar threshold. Policy travels with the org — agents and humans follow the same rules.
“Require voice confirmation on any envelope over $25,000.”
Field and mobile teams
Sales reps, inspectors, and contractors sign on site without juggling a phone and a clipboard. The ceremony reads each field aloud and records the spoken confirmation.
“Complete the work-order signature hands-free at the job site.”
Accessibility
Meet WCAG-aligned signing paths for signers with limited mobility or vision. Voice-guided ceremonies provide an alternative to draw-and-tap flows without a separate product.
“Offer voice-guided signing on every client-facing envelope.”
Agent workflows with human gates
Your agent drafts, routes, and tracks — but a human principal authorizes by voice before the envelope sends or before a delegated scope is exercised. The trail always shows who spoke, not just which API key acted.
“Agent prepares the SOW; I confirm by voice before it goes to the client.”
Legal & compliance
Defensible under Singapore ETA and Australia's ETA.
Voice authorization satisfies the same affirmative-act requirement as a click-to-sign. The difference is strength of attribution — enrollment binds voice to a principal, and every authorization event lands in the append-only audit log.
Affirmative act
Voice confirmation is an intentional, attributable act — the same legal category as clicking Finish. Consent to do business electronically is captured before authorization.
Principal binding
Enrollment ties voice to a verified identity. Delegation scopes and agent credentials inherit from that principal — on-behalf-of flows are never ambiguous in the trail.
SEA-ready evidence
Audit events structured for Singapore ETA review, Australia's ETA 1999, and PDPA-aligned retention. IMDA electronic-signature listing is on the certification roadmap.
Enterprise
Add voice authorization to your signing stack.
Voice-guided ceremonies and step-up authorization are included on Enterprise plans from $799/month — alongside custom domains, SSO preparation, and dedicated rollout.
Key takeaways
At a glance
- Voice enrollment creates a verified principal ID — every authorization is attributable to a real person.
- Step-up authorization plugs into the same envelope state machine as tap-to-sign; one audit trail either way.
- Asian-accent voice support for Singlish, Bahasa, Tamil, Vietnamese, and code-switching — not US-centric ASR.
- Delegation scopes let agents act on behalf of a voice-verified principal with explicit limits and revocation.