Designing a tool for BT customers to buy mobile phones on credit

Product design case study

Problem: New way of buying mobile phones that customers need to understand
My Role: Embedded UX designer
My approach: Led a discovery sprint and 7 iterative design sprints
Deliverables: Discovery playback deck, 7 interactive Axure prototypes
Customers: 10 qualitative interviews and 35 qualitative usability tests
Results: An intuitive purchase journey to buy a mobile phone on credit

iPhone 6 product page prototype


Handset Credit Sales (HCS) was a BT Mobile proposition which allowed customers to buy a mobile phone using a finance payment scheme which was separate to their SIM plan payment. It’s the same proposition which made giffgaff popular, only BT’s version was more flexible because customers could choose any upfront payment and length of contract.


As the embedded UX designer in the BT Mobile product team I helped them with the following objectives:

  • Redesign the BT Mobile purchase journey to allow for handset financing
  • Redesign the My BT account area to display handsets on finance alongside SIM plans
  • Increase sales of BT Mobile handsets and SIM plans
  • Increase customer satisfaction and NPS

My contribution

I guided the team through discovery and seven iterative design sprints each of which had a day of usability testing.

Most important mobile specs

We learnt that customers trust manufacturer websites to learn about the mobile phone specs and they visit provider websites to look for a good deal, so we surfaced only the most important specs at the top of the page – storage capacity, screen size, camera quality and battery life.

Finance package sliders

We tried many ways to explain how the proposition worked and found that allowing customers to interact with sliders was understood the most and came across as transparent, flexible and giving users the most control. This became a key module on the product page.

Package summary module

We designed a package summary module that updated dynamically as the user configured their options. This showed separate prices and contract lengths for the phone and SIM plan, and also displayed discount offers and their chosen upfront payment.


Payment schedule module

We found some customers wanted more clarity on how the separate phone and SIM payments would work so we visualised their payment schedule in a pop up.

Offer modules for existing BT customers

We displayed a current services module when customers were logged in so we can market the ‘handsets on finance’ proposition to existing BT broadband and SIM only customers.

Handset and SIM payment cards in My BT account area

We learnt customers accepted that they will pay separate direct debits for their phone and SIM plan but they wanted the information for both kept together, so we designed cards in the My BT account area that paired which SIM card was inside which handset on finance.

Handset plan statement

Because customers were using credit lending we designed a credit statement that adhered to strict Financial Conduct Authority (FCA) guidelines for explaining exactly where customers were in their repayment journey, along with access to signed agreements and annual statements.

Payment history timelines

We designed a payment history timeline in the style of a tube map to show a customer’s ‘repayment journey’ including their upfront, regular and missed payments.

Final thoughts

This project was paused and then cancelled after several months due to BT’s acquisition of EE, but I have no hard feelings. This was one of my most complex projects to date due to the way the proposition challenged customers’ mental model of buying a phone and SIM rolled into one payment, and the design constraints enforced by FCA regulations. I learnt a great deal and grew as a designer.

Interested in working with me? Check my availability.

Read more of my work.