T-Mobile · 2024 Web · App UX Designer

T-Mobile’s eSIM e-commerce experience.

Before iPhone 14, the first iPhone to ship eSIM-only, T-Mobile’s activation flow was losing customers at IMEI entry, device verification, and every fragmented step in between. We rewrote the experience around clarity instead of instruction.

RoleUX Designer, with senior designer & copywriter
TeamDesign, Research, Copy, Product
SurfaceBYOD · MyTMO · Purchase
StatusShipped, iPhone 14 launch
eSIM outcomes summary
→ OutcomesWhat this work moved

Four numbers, all moving the same direction.

+75%
Customer adoption
+87%
eSIM activations
+50%
eSIM awareness
81%
Satisfaction with SIM features

What it meant for the business: lower dependency on retail and phone support, faster adoption of a lower-cost digital product, and stronger first-time success that compounds into retention.

User journey and pain points across BYOD
§01The problem

Users dropped off the moment the flow stopped explaining itself.

Users attempting to activate eSIM struggled with unclear system feedback, fragmented steps, and missing guidance at the exact moments they needed it. The result was a flow with three compounding failure modes:

  • High abandonment during IMEI entry and device verification.
  • Increased reliance on customer support and retail assistance.
  • Lost conversions for a high-value digital product.

Three patterns kept showing up

Critical confusion around eSIM. Users were unfamiliar with the technology and how to confirm their device supported it, so they hesitated, second-guessed, or made errors that broke the flow.

Multi-step friction. The journey spanned multiple pages owned by different teams, with inconsistent feedback. Cognitive load piled up; uncertainty did the rest.

No contextual guidance. Terms like IMEI and EID were never explained in plain language. Users were left to translate jargon at the worst possible moment.

Team roles and collaboration
§02My role

UX Designer, splitting the surface with a senior designer.

I worked as a UX Designer embedded at T-Mobile from WongDoody, splitting design responsibilities with a senior designer across the eSIM onboarding experience.

Cross-functional partners

A copywriter on every screen of microcopy. UX researchers on what to test, and how. A product owner pushing for clarity on scope. The work shipped because the loop between those four roles was tight.

What I owned

User flows, interaction design, and content structure across BYOD, MyTMO, and the new-purchase journey, each with different ownership boundaries and different constraints.

Reframe diagram — uncertainty moments Reframe diagram — uncertainty moments 2
§03The reframe

From “improve the eSIM experience” to reduce uncertainty at the moments users hesitate.

Improving adoption was never about adding more screens or more instruction. The job was to remove the moments where users stopped feeling confident.

  • Reduce friction at the documented drop-off points.
  • Translate technical concepts into plain language, in context.
  • Give clear, immediate feedback during every critical interaction.
The problem wasn’t that users needed more help. It was that they needed help at the exact moment they were already lost.
IMEI step before and after redesign
§04Key decisions

Five moves that turned hesitation into completion.

1 · Simplifying the IMEI step

The IMEI input was the largest single drop-off. We rewrote technical terms in plain language, explained where to find an IMEI right next to the field, and rebalanced the button hierarchy so users wouldn’t click out of the flow by accident. User testing confirmed clearer copy and a calmer interface increased confidence and understanding.

2 · Embedding education in the flow

Instead of separate help pages, guidance lived where the question was asked, inline tips and modals at the exact decision point. Users no longer had to leave the flow to understand it.

3 · Streamlining multi-page flows

The original journey crossed pages owned by different teams. We minimized unnecessary steps, clarified the next action on every page, and added visual cues to keep momentum forward even where team ownership prevented full consolidation.

4 · Testing and iteration

15-participant remote unmoderated usability sessions plus a survey informed copy, hierarchy, and interface tweaks. Feedback consistently confirmed the experience felt clearer, easier, and more confidence-inspiring to complete.

5 · Designing within constraints

Backend limits and SEO requirements were real. We used inline guidance and modals to simulate a more linear, step-by-step experience without forcing changes to other teams’ pages.

Follow-on stepper concept
§05Reflection

What I’d carry forward.

The most impactful shift was focusing on reducing uncertainty rather than adding more instruction.

If I continued the work

  • Personalization based on device compatibility and user context.
  • More proactive guidance during edge cases and failure states.
  • Further simplification as backend constraints evolve.

A follow-on refresh moved toward a stepper-based, device-tailored linear flow. My contract ended around the time it was put on hold, details remain under NDA.

Next case → Introducing T-Mobile IDs.