From Scam Calls to Trusted Calls: Microtalk’s STIR/SHAKEN Journey

Back in March 2022, we introduced STIR/SHAKEN compliance and what it meant for UK businesses. At the time, robocalls were already a massive problem—nearly 2,000 robocalls were being made every second, and the FCC had identified them as the number one source of consumer complaints. Fast forward to 2026, and the problem has only grown more sophisticated.

STIR/SHAKEN—Secure Telephony Identity Revisited and Signature-based Handling of Asserted Information Using Tokens—was designed to combat caller ID spoofing, where scammers fake the number displayed on your phone to trick you into answering. The framework works by adding a digital certificate to SIP information, allowing receiving networks to verify whether a call’s caller ID is authentic.

Calls are rated with a simple A-B-C trust system:

– Full (A): The carrier knows the caller ID has not been spoofed
– Partial (B): The carrier originated the call but can not fully verify the caller ID
– Gateway (C): The carrier is not familiar with the caller ID

But here’s the thing—the regulatory landscape has shifted significantly since our first post.

The UK’s Unique Path: A Different Approach to Call Authentication

While the US and Canada have mandated STIR/SHAKEN, the UK has taken a more measured approach. Ofcom, the UK communications regulator, launched a public consultation in April 2023 to explore mandating STIR/SHAKEN for British telcos. However, the consultation revealed significant concerns.

Ofcom identified three key problems with a full STIR/SHAKEN mandate:

1. International calls can’t be fully verified – Overseas operators are not obliged to follow UK verification rules
2. Mobile number spoofing remains a gap – CLI authentication alone does not adequately address calls from abroad spoofing UK mobile numbers
3. Implementation is complex and costly – Alternative measures may reduce number spoofing more effectively and quickly

The result?

Ofcom abandoned the goal of imposing STIR/SHAKEN and instead opted for a flexible, technology-neutral approach. They are focusing on stronger Know Your Customer (KYC) controls and a central CLI database rather than mandating a single technology.

So, Why Does STIR/SHAKEN Still Matter for Your Business?

Despite Ofcom’s decision not to mandate STIR/SHAKEN, the technology remains critically important—and here’s why.

First, international business demands it. If your business calls the US, Canada, or France (which has implemented STIR/SHAKEN since 2023), your calls need to be authenticated to be trusted. Unauthenticated calls are increasingly flagged, blocked, or routed to voicemail. That’s lost opportunities.

Second, it’s about trust and reputation. When your customers see your business name on their phone, they need to trust it’s really you. Caller ID spoofing doesn’t just hurt consumers—it damages legitimate businesses whose identities are being faked by scammers.

Third, it improves operational efficiency. As we noted in our original post, when your contact centre uses STIR/SHAKEN, all calls are signed based on their trust level. Your team spends less time fielding spam calls and more time serving genuine customers. B- and C-rated calls can even be automatically diverted to voicemail.

Microtalk: Leading the Way in the UK

When we published our original post, Microtalk was—and still is—one of the only providers in the UK offering STIR/SHAKEN compliance. As a US FCC-licensed company, we recognised the importance of this technology early and became fully compliant ahead of the curve.

Today, Microtalk connects over 40 million calls a month. Being management-owned means we are not just another faceless carrier—we are dedicated to ensuring our customers get the support they need and are constantly on the lookout for new technologies that can help your business succeed.

In an industry where “grey routes” are increasingly becoming legal and reputational liabilities, having a trusted, STIR/SHAKEN-compliant partner isn’t just nice to have—it’s essential.

What This Means for Your Business

So what should you do?

Here’s our advice:

Assess your international calling needs. If you regularly call North America or Europe, STIR/SHAKEN compliance should be non-negotiable.

Choose a provider that’s already compliant. Do not wait for regulation to force your hand.

Partner with a provider that’s ahead of the curve—like Microtalk.

Educate your team. Make sure your contact centre staff understand what STIR/SHAKEN means and how it protects them and your customers.

Monitor call analytics. STIR/SHAKEN works better with more data. The more calls you route through a compliant system, the better the system becomes at distinguishing spam from legitimate calls.

Looking Ahead

The fight against scam calls isn’t over—and it probably never will be. But with STIR/SHAKEN as part of your communications toolkit, you are better equipped to protect your business, your customers, and your reputation.

As other countries continue to adopt caller authentication frameworks, and as the UK’s own CLI database takes shape, being STIR/SHAKEN compliant positions your business for the future of trusted communications.

At Microtalk, we are proud to be at the forefront of this movement.

Visit our website to learn more about how we can help your business stay secure, trusted, and connected.