Case study · UI/UX design · UK family money app

Bex,
for families.

A prepaid card and app for kids, an app for parents, and a Junior ISA for later. This was a redesign of an existing app, shipped after users complained and dropped off.

Shipped
Role · UI/UX designer
3 months
Parent app · Child app · Junior ISA · CTF
Light + dark

View the live site (opens in a new tab)

Overall activity

user activity after the core app redesign

Kids' savings

adoption of the Junior ISA and CTF feature

Reach

app downloads driven by the redesign

My role

UI/UX designer

The whole app: parent, child, Junior ISA and money flows.

Worked with

Developers, a manager and a PM

Designed alongside the people who built and owned it.

Timeline

3 months

For the whole app redesign.

01 · The problem

Families were leaving before Bex could help

Two users, one dependency

A parent signs up, passes ID checks, links a bank and adds money. Only then can a child start. One bad step stalls the family.

What was happening

Complaints about key steps and a high drop-off. Many families never reached a funded card, an active child or long-term savings.

Problem statement

Parents and children dropped out between download and a funded card. The design had to ask for less at the moments that need the most trust.

HMW 1

get a family from download to a funded card with fewer steps and less typing?

HMW 2

make moving money feel safe without slowing people down?

HMW 3

turn a spending card into a saving habit that lasts until 18?

02 · Research

What families needed from the journey

I started from the complaints and drop-off, then used a benchmark of UK kids' money apps and proto-personas to decide where the design had to work hardest.

The family journey · tap a step to see the screens

Step 1 of 5 · Child and parent connect

Link a child

Scan a QR code or enter six digits
If the parent can't be found, the child is asked to check the number and the parent gets a download link

What parents already expect

Bex's answer

Biometrics in the passcode pad.

Against GoHenry: fast return visits.

The gapNone of them made the long term easy. Bex could own it with a Junior ISA and a simple CTF transfer.

Two users, built from the complaints

Parent

"I'll finish setting it up when I have ten minutes."

Mary, two kids. Wants cashless pocket money, visibility, and a start on saving.

Blocked by long set-up, typing bank details, doubt about where money went.

Child

"Can I use it yet?"

Anika, 11. Wants her own card, a goal to save for, and tasks that earn.

Blocked by waiting on the parent to finish, and screens written for adults.

Proto-personas are assumption-based, not from interviews. Names come from the sample data in the designs.

03 · Approach

Four rules I designed against

One system, two apps

Shared top bar, input, button, PIN pad and options across the parent and child apps. Main action at the bottom.

Fewer fields

Let systems do the work: open banking to add money, Face ID or fingerprint to come back.

Design the unhappy paths

A name mismatch or a child who can't link gets a clear next step, not a dead end.

Make saving next

Junior ISA where parents already look. Paperwork for an old CTF handled for them.

04 · Two apps, one product

Every family action has two sides

Bex is a parent app and a child app that depend on each other. I designed them as one product, so what a parent does is visible to the child, and the other way round.

Parent home with each child's spends and savings — Parent appSees every child's moneyBalance, each child's spends and savings, Add Funds and Transfer in reach.

LinkThe child scans a QR code or enters six digits to join the parent's account.
FundThe parent adds money and moves it between a child's spends and savings.
UseThe child sees spends, savings, tasks, goals and when the next allowance arrives.
GrowThe Junior ISA has a child view, so the same account reads for both people.

Child home with spends, savings, tasks, allowance and goals — Child appSees what is theirsSpends, savings, tasks, allowance countdown and goals on one screen.

05 · Linking a child

Connecting a child never dead-ends

Scan or type six digits

A child links to their parent by scanning a QR code or entering a six-digit code. If Bex can't find the parent, the child isn't left with an error.

1
Scan the QR code or enter the six digits.
2
Parent not found? The child is asked to check the number.
3
The parent gets a download link, so the family can carry on.

06 · Adding money

From typing bank details to tapping your bank

Add funds · typing vs tapping

Pick your bank. Approve. Done.

Parents choose their bank and approve the payment in their own banking app through open banking. Saved banks come back as cards, so the next top-up is an amount and a tap.

RecurringSchedule monthly, weekly or daily, or top up automatically when the balance drops below a chosen amount

Bank details

Account nameGeorge Miller

Sort code00-00-00

Account number12345678

Continue

Typing bank details3 fields, 14 digits

Pick your bank

Select a payment bank account

Royal Bank of Scotland Monzo Barclays Natwest

Approve in your banking app✓ Approved

Tapping your bank1 tap, then approve

One-off top-up

Enter amount — **Amount first**Bank chosen next

Saved banks shown as cards — **Pick a bank**Saved banks come back as cards

Transfer submitted confirmation — **Submitted**Amount and transaction ID

Recurring top-ups

Add funds with saved bank card — **Saved bank**With recurring status

Schedule top-up — **Schedule**Amount, frequency, day

Auto top-up threshold — **Auto top-up**Below a threshold

07 · Saving for later · +47%

A Junior ISA parents actually open

Shown on the parent home with a reason to act (opening one removes card fees), four labelled steps, and CTF paperwork handled for them.

Family list with Start per child — **Start per child**Opened accounts listed below

Risk warning, step 2 of 4 — **Risk in plain words**Documents in one list, step 2 of 4

Slider for cash and stocks mix — **One slider**Cash or stocks, changeable later

Estimated value by age 18 — **See the future**Estimate at 18 updates live

CTF details step 3 of 3 — **CTF in 3 steps**You, your child, the fund

Let Bex handle the form or print it yourself — **Who does the paperwork**Bex posts a form, or print it

Form and prepaid envelope on the way — **Clear next step**With tracking

"Let bex handle everything for you."

08 · Sending money out

Catch the wrong account before money leaves

UK banks check that the payee name matches the account (Confirmation of Payee) and payments need strong authentication. Each result is its own state with one clear action.

Confirmation of Payee

State

State=Typing

Partial match

The field flags itself in place

As the recipient name is typed, a partial match is flagged right in the form, before any decision.

09 · Learning for kids

BexBuddy, an AI guide that knows its limits

The best feature is what it won't do

Who would win, Batman or Superman?

That's a great question, but it's not something I can help you with. My knowledge is limited to finance topics. Maybe you can ask a grown-up for help.

How do I boost my savings?

Answered in plain words.

Typing a keyword shows suggested questions, so there is no blank chat box. Past questions are saved and filtered by topic.