eSIM Modernization
Bringing T-Mobile to the next generation of SIM technology
2022 / Figma / My Role - UX Designer
Team - Lead UX Designer, UX Copywriter, Product Manager,
UX Researcher
eSIM Modernization is a project aimed toward increasing awareness of what eSIM is, eSIM activation instructions, SIM swapping within the Purchase (buying a phone on T-Mobile's website), and BYOD (bring your own device) flow for new (prospect) and existing customers. This project covers web, mobile, and the T-Mobile app.

An eSIM is an electronic SIM card already in the phone so people don't have to get a physical SIM card to activate their phone. This reduces wait time for users who would've bought a physical SIM online or saves them a trip to their local T-Mobile store to buy one.
The Problems
  • 4 out of 5 customers do not know what an eSIM is
  • T-Mobile does not have eSIM messaging or education
  • A high volume of calls to customer service regarding failed eSIM activations
  • Get T-Mobile ready for the new iPhone release
Measuring Success
  • Increase eSIM awareness within the BYOD (bring your own device) and purchase flow
  • Increase user completion rate of eSIM activations
  • Decrease calls to customer service regarding failed eSIM activations
  • Increase user satisfaction with the BYOD flow
Design Process
*Results at the end of the case study
Existing Research
Simplify Steps & Show Progress
  • People that are visiting the BYOD page are serious about either switching to T-Mobile as a new customer or swapping SIM cards as a current customer
  • Use human language to explain technical terms and processes like IMEI and EID numbers and how to find them on your phone.
  • Only show relevant information to the users once they started the process. Users are shown deals they don’t qualify for currently.
  • Decrease the amount of CTA's users see on the BYOD page. Users don’t know which one to click.
  • Add something to show users what step they’re on in the process.
  • Clarify the steps on the BYOD page above the IMEI checker to match the most updated process.
  • Ensure minimal steps are needed for users to be successful while informing them of their next steps.
Competitive Analysis
Balancing Information Shown
  • Multiple carriers aren’t showing a detailed list for IMEI results
  • Mint and Cricket have the IMEI checker on the BYOD page
  • Only AT&T and T-Mobile explain what an eSIM is
  • Google Fi provides a lot of info on your phone's compatibility with their network, similar to T-Mobile
  • Most explain the steps on how you bring your own device to their network
  • Google has users select the brand and model, not their phone's IMEI number
  • AT&T has the user decide whether they’re a prospect or a current customer wanting to add a line
  • All have very few steps for prospect customers
  • Mint Mobile tells the users what step they’re on in the process
  • Mint Mobile also lets users decide to enter their phone's IMEI number or by brand and model.
Benchmark Testing
Journey Mapping
A Terrible Experience
Existing BYOD flow - prospect customers
  • There's a lot of information on the BYOD page, not sure where to go or what to click
  • Check compatibility is under the second step but the IMEI checker is below it on the page
  • Too many CTA's on the page
  • Users have to select their plan choice two times

Existing Add-A-Line flow - current customers
  • Doesn't inform users how much their new monthly bill will be, only shows the added cost of the line and phone
  • Doesn't let users change their plan
  • Shows the deal the company wants to promote even if the user isn't eligible for it
  • The pill button is almost hidden on the cart page showing the user they've added a new line
User Flows
*MyTMO is what T-Mobile calls their site when a customer is logged into their account. Giving customers access to their account details page.
Testing Our Designs
We collaborated with user researchers to conduct a remote, unmoderated usability session with 15 participants who were primary account holders (PAH), had a Post-paid plan, and were a mix of genders and ages between 18-65. Participants reviewed a click-through desktop prototype and were asked to think aloud when given task scenarios and survey questions.
Big Changes to Come
  • Updated copy on pages to better explain important details that some users struggled to understand
  • A few UI changes from feedback from the team like horizontally stacking the buttons. Discussions were had about balancing eSIM priority from the business side and ensuring physical SIM card was still shown equally as viable.
  • Instructions page was updated with new copy and formatting.
  • More impactful changes have been made for a future release of the project which I cannot discuss yet.
Final Designs
Check out our project on T-Mobile's website.
Results & Reflection
Boosted T-Mobile eSIM awareness by 50%, raised eSIM customer adoption by 75%, and attained an 81% satisfaction rate for SIM features on T-Mobile's website.
These numbers were shared by the Lead UX Designer on the project. Since I wasn't a FTE T-Mobile employee, I could not get access to any results or more in depth results myself.
What could be improved
The Product Manager for this project kept us designers and the developers seperate the entire time. Myself and the Lead UX Designer tried pushing to meet with them and establish a line of communication but the Product Manager ultimately refused. This resulted in some confusion on what was and wasn't possible because of the game of telephone being played through the Product Manager. For one instance, the image of the device on the BYOD results page not being possible was not told to us.
This project had a strict timeline that made many avenues impossible to explore and required us to use existing research at the beginning of the project.
Next Steps
Release the new BYOD experience that supports different types of devices like smartphones. It also fixes all of the pain points we discovered at the beginning of the project.