The other day, I got a call on my landline. Yes, my landline. When I answered, an AI-style voice started reading out a string of random numbers. I mentioned it to colleagues, and the responses were instant:

“Sounds like the start of The Ring…”
 “That was probably Pelin!”

You can just reply “LoL” when colleagues are teasing you.

But what do you do when your stakeholders ask:

“Who even uses landlines anymore?”

It was 2023, after all. Smartphones dominate, digital experiences are optimised for mobile-first interactions, passkeys and multi-factor authentication apps are the new gold standard.

When we design for the “default user”, we often assume they:

  • own a smartphone
  • have stable internet access
  • are somewhat confident navigating digital products

What about the people who don’t fit that mold?

Not everyone has a smartphone, can receive a mobile OTP, download an app, or scan a QR code.

When we are talking about a public-facing NHS digital service, such oversight can unintentionally exclude certain groups, potentially limiting their access to vital health services.

How We Challenged Assumptions And Shifted Mindsets

Building a case: Using stats and data

First, we turned to the data:

  • 19% of UK households still have a landline as their primary phone (Office for National Statistics).
  • Approximately 33 million patients in the Personal Demographics Service (PDS) have a landline number listed, while 7 million patients have no mobile phone number on record.
  • UK mobile coverage report lists Wales as one of the regions with high proportions of rural areas to experience poor mobile network coverage, making landline even more relevant as this NHS service had plans to integrate with NHS Wales platforms.

If a service is meant for everyone, shouldn’t “everyone” actually mean everyone?

Reinforcing the case: meeting legal standards

We advocated that inclusivity isn’t  just a best practice — it is a legal expectation. UK public services must comply with UK government policies which set clear requirements for accessibility and inclusivity in digital services.

Beyond the user experience, it was about ensuring fair and equal access for everyone, as mandated by law.

Bringing user needs to the forefront

Once we had the team’s attention, we needed to prove that landline authentication wasn’t just a “nice-to-have”— it was a real issue affecting actual users.

We ran three rounds of moderated usability testing with 24 participants with diverse needs.

Sharing real user stories with stakeholders

“Can I remove the mobile phone number from my account now? I was using my son’s mobile phone to log in.”

User feedback brought the issue to life in a way that numbers and stats couldn’t. 

  • There are people with low digital literacy or disabilities who struggle with mobile authentication.
  • Some users live in regions with unreliable mobile signal, making mobile authentication difficult or even impossible.
  • Some users rely on family members’ mobile phones, meaning they don’t always have immediate or independent access to their own accounts.

These weren’t edge cases. These were people who risked being locked out of a vital public service because of an unchallenged assumption.

The shift: From skepticism to action

By combining user research, data, and collaboration, we were able to shift the mindset of the team. We achieved this by:

  • running sessions with stakeholders to align on the importance of inclusivity.
  • iterating frequently, sharing progress and insights to ensure alignment.
  • involving the wider team in brainstorming and prioritisation sessions to refine the approach.
  • engaging with external services (e.g., PDS) to gather insights on landline usage in patient records.
  • working with policy experts to ensure alignment with inclusivity requirements.
  • engaging cybersecurity experts to ensure landline implementation met standards.
  • assisting the support team to prepare training materials for landline related queries.
  • collaborating with the engineers to map technical processes and user journeys.
  • working with the data team to track user adoption post-launch.

The Result?

When landline authentication went live, this happened:

  • 19,000+ users registered with a landline—people who would have otherwise been locked out of the service.
  • 60,000 users added a landline from settings as an authentication option.
  • 50,000 successful logins using landline OTPs.

The lesson: Designing for the “average user” means leaving people behind

Innovation isn’t just about what’s new—it’s also about what works for everyone.

And sometimes, that means challenging assumptions, looking at real user needs, and proving, through research and data, that inclusivity isn’t optional.

Because when it comes to public services, true success isn’t measured by how seamless an experience is, it’s measured by how many people can access it in the first place.