Rich Call Data and STIR/SHAKEN: How Verified Caller Details Build Trust

Key takeaways

RCD sits on top of STIR/SHAKEN and lets businesses control what recipients see.
It can show your business name, logo and a short reason for calling.
Unlike CNAM, RCD comes from the business and is protected by cryptography.
Adoption is still early, so test how your calls appear on real devices.

More and more people ignore calls from numbers they don’t know, and the telecom industry has responded with technology designed to cut fraud and verify who’s calling. STIR/SHAKEN already makes caller ID spoofing harder. Rich Call Data (RCD) builds on that foundation by giving businesses control over what recipients actually see when their call comes in.

A quick look at STIR/SHAKEN

STIR/SHAKEN is an authentication framework that uses digital certificates to "sign" calls as they move through networks.

STIR (Secure Telephone Identity Revisited) checks that a call really comes from the number shown.
SHAKEN (Signature-based Handling of Asserted information using toKENs) is how carriers put STIR into practice.

Attestation levels, and the gap they leave

Every signed call receives an attestation level showing how confident the carrier is in the caller ID:

A (full): the carrier has verified the caller is allowed to use the number.
B (partial): the carrier knows who’s calling but isn’t sure they’re authorised to use the number.
C (gateway): the carrier can’t confirm whether the caller ID is accurate.

There’s a catch: recipients never see these levels. Most screens still show nothing but a phone number. RCD is designed to close that gap.

What RCD achieves

With RCD, businesses can add details so people know who’s calling and why. That can include the business name, a brand logo and a short call reason such as "Appointment reminder" or "Customer service."

Compare that with traditional CNAM, which shows a business name of up to 15 characters. With CNAM, the recipient’s carrier looks the name up in a third-party database, so it can be wrong or out of date. RCD is supplied directly by the business, which means you control what people see.

CNAM vs RCD at a glance

	CNAM	RCD
Where the data comes from	Third-party database lookup by the carrier	Sent by the business with the call
What it shows	Up to 15 characters of text	Name, logo and call reason
Security	Easier to spoof	Protected by cryptography
Cost	Often involves carrier fees	Delivered as part of the call setup

How RCD works

Authentication and signing

RCD relies on STIR/SHAKEN to authenticate the call. The service provider creates a PASSporT (Personal Assertion Token) and places it in the SIP Identity header, which is used to set up and authenticate IP-based calls.

What gets sent

Your business details travel with the call. The logo itself isn’t sent as an image, since it would be too large. Instead, RCD carries a secure link to the image along with a cryptographic hash that reveals any tampering.

In transit

Signatures and certificates prevent anyone from changing the RCD data as the call moves between networks.

Verification and display

The receiving carrier checks the signature, validates the certificate and pulls the RCD details. Your business name, logo and other information then appear on the recipient’s screen.

Why RCD matters for your reputation

Higher answer rates: a recognisable logo and clear reason make people more willing to pick up.
Brand protection: because RCD is tied to STIR/SHAKEN, it’s extremely difficult for fraudsters to alter your details or logo.
Fewer spam flags: carriers and analytics engines are less likely to flag verified RCD calls.

Where RCD stands today

RCD is still in its early stages. Not every device supports it yet, and its long-term success depends on carriers cooperating and deploying it across their networks. That makes real-world testing essential. With Device Cloud, you can see exactly how your calls appear on real phones across major networks.

In the meantime, the best preparation is to keep your numbers clean, aim for full attestation and keep your business details consistent everywhere they appear.

Why logos are sent as links, not images

It might seem simpler to send a logo directly with each call, but image files are far too large to travel inside call signalling. Instead, RCD includes a secure link to the logo and a cryptographic fingerprint of the file. When the receiving network fetches the image, it checks the fingerprint. If anyone has swapped or altered the logo, the fingerprint won’t match and the image won’t be shown. It’s an elegant way to keep branding both rich and tamper-proof.

Writing effective call reasons

The reason for calling is often the most persuasive part of an RCD display. Keep it short, specific and honest, for example "Appointment reminder," "Order update" or "Fraud alert." Avoid vague or salesy text, which can make people less likely to answer. If you run different campaigns, consider using different reasons so people always know what to expect.

The business case for RCD

For teams that rely on outbound calls, even a modest rise in answer rates can mean many more conversations each day. RCD also protects your brand: because the details are verified, scammers find it much harder to borrow your identity. And because verified calls are less likely to be flagged, RCD supports the long-term health of your numbers.

Getting started

Confirm your provider supports STIR/SHAKEN signing at A level.
Choose a branded calling or RCD provider and register your business details.
Prepare your logo and call reasons.
Test on real devices across major networks.
Monitor results and keep numbers clean.

Frequently asked questions

Does RCD replace CNAM?

Not yet. Many networks and devices still rely on CNAM, so both matter for now.

Will RCD stop my calls being flagged?

Verified RCD calls are less likely to be flagged, but reputation still matters, so keep monitoring your numbers.

How do I know if my RCD is displaying?

Test on real devices across major carriers, since support varies.