Reducing Social and Cognitive Friction in Shared Expenses
Under 1:1 mentorship, I worked through the end-to-end design process for a bill-splitting feature within Ap, Iran's largest payment app, The solution is estimated to drive 5.5M+ new monthly P2P transactions and a 3-5 point lift in 30-day retention. I was responsible for user research, competitive analysis, and end-to-end product strategy.
CONTEXT
Splitting bills among friends is a routine part of daily life in Iran, yet most payment apps treat it as a simple math problem rather than a social one. This gap leaves users burdened not by calculation, but by the discomfort of asking others for money.
RESEARCH
Starting research and found out: Shared Costs, Scattered Tools.
Users often rely on a mix of manual and scattered tools to split group expenses.
chat apps (WhatsApp/Telegram)
basic bill-splitting apps
card-to-card transfers
often leading to missed payments
time-consuming
error-prone
which are
Yet, data shows that 65% of people already use internet banking.
Why the “Asan Pardakht” APP?
Ap (Asan Pardakht) is one of Iran’s major PSPs, offering a wide range of payment services through full access to the national banking network (Shetab). In this project, I explored the opportunity of designing a bill-splitting feature within Ap, leveraging its strong payment infrastructure from a product and UX perspective.
The “Ap” app currently has the largest market (45%) share among payment applications in Iran.
The “Ap” app has over 37M active users.
The question is:
"How might we create a simple and reliable experience for calculating shares and handling P2P payments, so that users with different bank cards can pay their part quickly and securely?"
Starting with conducting a survey
51.2%
of people mentioned that accurate and fair calculation matters to them.
36.5%
of people mentioned that they don’t remind the other person about the money they’re owed.
44.7%
of people use Telegram or phone notes.
Users struggle with unclear payment tracking, the discomfort of asking for money, and manual calculations.
UNDERSTANDING USERS CORE NEED
Then the interview
I conducted 10 user interviews to better understand people’s needs and pain points around splitting shared costs.
Realizing How Users Struggle With Social Pressure & Cognitive Load
When it comes to splitting the cost, how do you usually handle it?
What are the challenges?
In this situation, I’m not comfortable reminding them, so I just let it go.
Because even that last small percentage with the tax part is really hard and complicated for me to calculate.
I don’t feel comfortable reminding them. It’s fine if it’s a subtle reminder, but I don’t really know how to do that.
DEFINING USER ARCHETYPE
Grouping our users into 2 main archetypes:
Sara - Manual Calculator
Sara wants a simple, reliable way to calculate and track shared expenses without switching between apps or double-checking numbers.
Ethan - Constrained
Ethan wants shared payments to resolve themselves automatically without him needing to chase people.
AND HERE IS THE STORY
It Always Starts Simple, When the Bill Arrives, So Does the Tension
OUR OPPORTUNITY
What is the opportunity?
Connecting Calculation, Reminders, and Payment in One Flow
Competitive tools either calculate expenses or process payments but none connect the two. Iranian users are left navigating a fragmented flow across multiple apps, VPN barriers, and uncomfortable social dynamics. This gap creates a clear opportunity for "Asan Pardakht" to deliver the end-to-end cost-splitting experience built.
BEFORE
AFTER
WHATS IN MARKET
What do other apps do?
Simple group dashboard
Users can easily create a group and split the bill through the app's intuitive dashboard. The tradeoff
Running balance / group ledger
you log expenses, the app maintains running balances, and you settle up when convenient. This makes it the go-to for long-term shared living arrangements.
No-frills, no-account simplicity
Users love Splid for what it doesn't do: no ads, no subscription, no sign-up required, and it works offline. It's a clean, no-account tracker but lacks receipt scanning, real-time multiplayer, and any tax/tip handling.
Cent-level precision + easy migration
Handles equal splits, parts, and custom amounts with cent-level precision. useful when the bill has ugly numbers and no one wants rounding drama. It can also import existing Splitwise groups, making it easy to switch over.
PRIORITIZATION MATRIX
Let’s ideate and explore solutions!
I mapped the solution ideas on an impact–effort matrix to see which ones matter most. This revealed quick wins with big improvements for payments.
Selective Expense Visibility (Partial Group Sharing)
Adaptive Reminder Tone Modes Based on Group Context
Flexible Grace Period Option for the Group Admin (Bill Owner)
Personalized Reminder Settings per User
Behavior-Based Payment Scoring with Gamified Indicators
reminder
Flexible In-App Payments with Auto-Settlement
Group Expense Insights & Reports
Real-Time Payment Status with Badges
Automatic P2P Payment Confirmation (No Screenshot Required)
Flexible Expense Splitting Models
Reusable Groups with Auto-Close & Reopen Option
Draft Mode & Offline Sync
Smart OCR Invoice Scanner (Persian & English) with Auto Tax Calculation
VISUAL DESIGN
Creating a more straightforward, transparent, and connected experience
IMPACT
Expected KPI Impact
Increase in Transaction Volume
Group expenses generate multiple payments per event. Enabling end-to-end settlement inside Ap could increase monthly peer-to-peer transactions.
Higher Retention & Repeat Usage
Unlike one-time transfers, shared expenses are recurring social behaviors (dining, trips, events). This could improve 30-day retention by encouraging repeated engagement within group contexts.
Growth in Wallet Adoption
Auto-settlement and seamless in-app payments create a strong incentive to preload wallet balance, potentially increasing wallet activation rate and stored balance usage.
AHA MOMENT
Users were not struggling with calculations, they were struggling with the emotional burden of asking for money.
This shifted the design direction from simply “making math easier” to reducing social and cognitive friction through automation, transparency, and system-led reminders. The breakthrough wasn’t about smarter calculations, it was about removing the emotional labor from cost splitting.
NEXT STEP
If this project were to move forward into implementation, the next focus would be validating assumptions and measuring real behavioral impact.
Usability test
Conduct usability testing on the reminder and payment flow to ensure automation reduces, not increases, friction.
Track wallet activation
Track wallet activation and auto-settlement adoption as leading indicators of recurring usage.
A/B test
A/B test reminder timing and frequency to avoid notification fatigue.
Refine edge cases
Refine edge cases such as partial payments, late payments, and group drop-offs.