Shipped
Web
B2C SaaS
Timeline
My Role
Team
Tool
Overview
Paywork is an invoicing and payment management service for small business owners who prioritize speed and efficiency in their daily operations. Users can handle the entire business transaction workflow in one place, from estimates to tax invoices to settlements, across both mobile and web.
In this project, I redesigned the entire tax invoice experience by restructuring the form layout and automating the data entry workflow to lower the barrier to Paywork's core paid feature and drive user activation.
Key Objectives
Paywork’s priority was increasing paid plan conversion. Tax invoicing was the core feature of the paid tier, yet in-product usage sat at just 13%. Low adoption of a paid feature meant users weren't experiencing the value that would justify paying.
Before we could move the conversion needle, we needed to remove the usability barriers around this feature so users could actually feel what the product was for.
Research
I conducted interviews with 30 small business owners who issued 50–60 tax invoices per month on average.
The core question: if users were already creating estimates in Paywork, why were they leaving to issue tax invoices elsewhere?
Key Findings
Users were blocked by two things: an unfamiliar form structure and repeated manual data entry.
Problem 01: The input form felt unfamiliar
"How am I supposed to fill this out?"
"Where should I enter this information?"
The long scroll made it hard to understand
where each field belonged.
Problem 02: Users had to re-enter existing data
"I already have all this data."
"What if I make a mistake?"
Design Solution
Solution 01: Mirror the paper tax invoice format
Redesigned form layout
I redesigned the form layout to follow the tax invoice format users were already familiar with.
In Korea, many small business owners handle tax invoices as part of their daily business operations, so the format was already familiar to Paywork’s core users.
By bringing that familiar structure into the product, users could start filling out the form without having to learn a new layout.
Before
After
Solution 02: Turn existing data into a one-click invoice
One-click conversion
Users who created an estimate in Paywork already had the necessary client, item, and amount information saved.
I designed a one-click conversion flow that turned an existing estimate into a tax invoice, eliminating the most repetitive step in the workflow.
Bulk upload
For users issuing tax invoices without an existing estimate, item and client details still had to be entered line by line.
Since many users already managed this information in spreadsheets, I designed a bulk upload flow that let them import multiple invoice items at once.
Before
Manually entering item details and amounts increased the risk of errors.
After
Impact
3x
increase in tax invoice issuance rate, from 13% to 42%.
2
enterprise partnerships with Hana Bank and KG Mobilians, a leading Korean payment processor.
“
Before, I had to manually enter all invoice details into a separate government tax system. Now, with automation and one-click conversion from estimates, it saves so much time and makes the process much easier to manage.
small business owner in their 50s
Takeaways
The highest-impact decision in this project wasn't a feature. It was copying a piece of paper. Users didn't need a better form. They needed a familiar one.
What's a standard layout for people in tech was a source of cognitive friction for independent business owners. The best interface isn't what we believe is right.
It's what users already know.