Your friends can charge your bank account.
That’s the magic of a shared card that splits and pays at once — and it’s the fear. Letting a friend’s tap pull money from your account is the thing that stops people turning it on. The speed you’ve nailed. The trust is a design problem.
I’m Carl. I run Sunday, product design for fintech, ex-Swedbank. I kept circling the screen that makes instant charging feel safe, so I designed my take. It’s live, just below.
The concept, running
It’s live. Split a bill, tap someone out, settle.
How I’d make instant charging feel safe.
Cino already cracked the hard part — split and pay at once, money straight from each person’s bank. What’s left to design is the feeling: making an instant, involuntary charge feel like control, not exposure. That’s three moments — the consent, the fairness, and the people who weren’t there — and it’s where I focused.
Four decisions, and why:
€24.00settled
Sam paid · charged from your own bank
I made instant charging feel like consent
The scary part of a shared card is that a friend’s tap pulls money from your account. So the settle screen shows it was fair, instant, and — the key — auto-approved under a cap you set. Anything bigger asks you first.
You€32.00
Sam€32.00
Mara€32.00
JoNot inI solved the person who wasn’t there
It’s the most-felt friction in any split, and it’s missing from the flow today: someone skipped the dinner. One tap drops them out, the shares recalculate, and they’re simply never charged.
€0
Nobody owes anybody
I killed the debt ledger
Splitwise is a list of who owes whom. Cino’s whole magic is that the balance is always zero — so the group reads “nobody owes anybody,” a feed of settled moments, not running debts.
A face, not a fintech
A coin mascot, a celebration when a split lands — warmth where the money moves.
I gave it a personality
The audience is Gen-Z and the angel is Cleo’s founder. So this isn’t fintech-cold — it has a coin mascot, a celebration when a split lands, and warmth exactly where the trust has to live.
Anyone can split a bill. The work is making a friend charging your account feel safe.
A bit about me.
I’m Carl. I run Sunday, a product-design studio for fintech. Before this, Swedbank, one of the Nordics’ largest banks. I work embedded, like part of the team, from first research to the final interface. No handoffs.
I built this from the outside, on your app and your positioning alone — no brief, no access. You’ve clearly got design in your DNA, so take it as a conversation-starter, not a critique. With your real flows behind it, it gets a lot sharper.
“He champions user-centered design without ever losing sight of how it drives real business outcomes. That balance is rare.”
Joackim Zwahlen — UX Lead, Swedbank
That’s the idea.
I made this because the problem stuck with me. If it’s useful, grab 30 minutes below and I’ll walk you through where I’d take it next. If you want it real, a two-week sprint makes this flow production-ready in your app. If not, no hard feelings. I’ll be watching what you build either way.