A legitimate business call can fail before the customer answers. Carriers and devices evaluate caller identity signals, call history, and reputation, while customers increasingly ignore unfamiliar numbers.
Twilio announced on November 5, 2026 that the Voice API Call resource now returns STIR/SHAKEN status. The stir_verstat property is available when an application fetches a call or reads a list of calls. Twilio recommends using it to confirm A attestation and identify calls signed at B or C for remediation.
What STIR/SHAKEN attestation means
STIR/SHAKEN helps carriers assess whether the calling party is authorized to use the displayed caller ID. A attestation generally indicates the provider knows the customer and the customer has the right to use the number. B indicates the customer is known but the provider cannot fully attest to the number. C indicates the provider originated the call but cannot attest to the customer or number.
Attestation is not a guarantee that a call will be answered, labeled correctly, or delivered. It is one signal within a broader calling ecosystem.
Why SMBs should monitor the status
Businesses use outbound calls for callbacks, appointment reminders, service updates, lead follow-up, payment questions, and emergency coordination. A lower attestation level may reveal a configuration, number ownership, routing, reseller, or origination issue.
Without API visibility, teams may see only falling answer rates and assume customers are uninterested. Adding the status to call records makes investigation more specific.
A practical customer-response example
A home-services company returns missed calls through an automated callback workflow. Answer rates decline after traffic is moved to a different application route. The CRM records dialed and completed calls but not attestation.
The company begins storing stir_verstat with the call ID, number, campaign, route, outcome, and customer source. It discovers a cluster of B-attested calls on the new route. Staff investigate number configuration with the provider while continuing urgent callbacks through an approved alternative.
The business does not tell customers that A attestation guarantees legitimacy. It uses the signal internally to improve operations.
Build the signal into call operations
Store it with the authoritative call record
Capture the Twilio Call SID, direction, from and to numbers, start time, status, application, attestation value, and business workflow. Minimize personal data and restrict access.
Segment by route and purpose
Compare callbacks, reminders, support, sales, and verification calls separately. A single account-level average can hide one failing route.
Join with customer outcomes
Measure answer, voicemail, busy, failed, completed, callback received, appointment confirmed, and human follow-up. Attestation has operational value when it helps explain or improve those outcomes.
Escalate patterns, not isolated noise
Create a threshold for repeated B or C values by number, route, provider, or application. Preserve representative call IDs and timestamps for support.
Implementation guidance
1. Fetch the new property
Update the server-side SDK and data model as needed. Handle missing values without breaking the workflow. Test inbound and outbound scenarios relevant to the business.
2. Verify number ownership and configuration
Confirm the organization, calling number, trunk, application, and origination route are configured as intended. Keep registration and brand records current.
3. Protect caller reputation
Call people who expect the contact, honor consent and opt-outs, use reasonable frequency, identify the business promptly, and avoid misleading caller ID practices. Attestation cannot compensate for unwanted calling.
4. Create a remediation runbook
Document who reviews lower attestation, which provider or carrier evidence is needed, how urgent calls continue, and when a route should be paused.
5. Preserve human escalation
If a callback is not answered or a route is degraded, create a visible task. Do not mark the lead complete simply because a call was initiated.
Measurement guidance
Track attestation distribution, answer rate, voicemail rate, failed calls, customer callbacks, complaint rate, appointment confirmations, route changes, and time to remediation. Compare similar call purposes and time periods.
Watch for tradeoffs. A route change that improves attestation but creates delay, audio problems, or workflow errors is not a complete improvement.
Connect STIR/SHAKEN to Maya
Maya is a managed AI Customer Response System that may support inbound phone answering, callbacks, qualification, structured summaries, and human escalation. Its workflow follows Respond → Qualify → Act → Handoff.
DIGIMAR’s Maya service and automation work can incorporate call-status evidence into CRM records and recovery tasks when the required Twilio configuration and permissions are available.
Next step
Add stir_verstat to a call-quality report, segment the last relevant sample by route and purpose, and investigate repeated B or C values with supporting Call SIDs. Connect every unsuccessful customer contact to a clear next action.
Use attestation without misleading customers
STIR/SHAKEN is an internal trust and routing signal, not a marketing badge. Avoid telling customers that a call is “verified safe” solely because it received A attestation. A legitimate number can still be misused, and a lower attestation can result from routing rather than fraud.
Customer-facing trust should come from consistent caller ID, accurate business naming where supported, expected contact, immediate identification, and a safe way to call back through a published number. Train staff and automated systems never to request passwords, full payment credentials, or verification codes unexpectedly.
Coordinate voice, SMS, and web channels
If a customer misses a call, a permitted SMS or email can explain the reason and next step. The message should reference the business, not expose sensitive details, and respect consent. Website contact information and Google Business Profile should use consistent numbers and hours.
Investigate call-label complaints
Capture the destination carrier, device behavior, timestamp, calling number, attestation, and call purpose. Look for patterns instead of relying on one screenshot. Review whether contact frequency or poor targeting is generating legitimate complaints.
Operational review checklist
- Confirm numbers and routes are still authorized.
- Compare attestation by provider and application.
- Review complaints and opt-outs.
- Test published callback numbers.
- Verify unresolved calls create owned tasks.
Run this review after carrier, trunk, application, number-registration, or campaign changes.
Review with customer-service teams
Share attestation trends with the people who handle callbacks and complaints. Their observations can reveal number-label changes, unexpected call patterns, or confusing scripts before dashboards do. Combine that qualitative evidence with API records, and document the corrective action so the same routing problem is not repeatedly rediscovered.