E-Filing
Online tax filing made easy. Turning critical usability issues into a intuitive experience for Thai citizens.
In Q4 2021, I had the opportunity to help the Thai Revenue Department redesign their E-Filing service, a website that was used by over 10 million Thai citizens every year to file their personal income taxes online.
Role
UX Designer
Employer
Ahancer UI/UX Agency
Timeline
Oct - Nov 2021
AReas
Research, Strategy, Design
The Thai Revenue Department redesigned their E-Filing portal without any user research. As a result, when they finally tested it after development, many participants found it “more difficult to use than the old one”—raising serious concerns about their upcoming public launch.
The new E-Filing portal launched in March 2022, receiving a 90% customer satisfaction score and positive public reception following a complete redesign driven by comprehensive usability testing and supported by a robust design system.
Preview
Select the right tax form and pre-fill it instantly
The My Tax Account API automatically retrieves your financial data from employers, brokerages, and insurance companies—eliminating manual data entry and ensuring accuracy.
File with confidence
Income categories are clearly organized for easy scanning, with optimized interactions that guide users to the right fields without confusion.
Clear tax breakdowns and next steps
Detailed breakdowns show how your tax calculation was determined, while a streamlined process handles refunds when you've overpaid.
To improve the E-Filing experience, we first needed to understand why it was difficult to use. I conducted evaluative research with 12 participants, 6 novice and 6 experienced tax filers (2 years or less vs 3 or more years), triangulating qualitative feedback with usability metrics .
25% of participants failed to complete a basic salary income entry task
The interaction for entering regular salary income introduced unnecessary friction. While most users were eventually able to complete the task, 25% failed entirely—revealing a critical breakdown in a core flow that should feel effortless.
63% of participants failed to enter additional income — a key drop off in the experience
A majority of users struggled to report income from business activities and mutual fund dividends—two common scenarios that revealed major usability gaps in the existing flow.
I identified a total of 18 distinct usability issues, but will zoom in on the top three findings that significantly hindered many participants from successfully completing their tasks.
FINDING #1
Most participants had a hard time finding the correct income tax type because of the poor organization and lack of categorization.
FINDING #2
Many participants did not know how to input their taxable income because they kept trying to click on the disabled field.
FINDING #3
Most participants were unable to fill out their investment income and other income sources detail properly due to unclear labels instructions and jargon.
Triangulating qualitative feedback with usability metrics
In line with our participants’ comments, I also observed that the usability metrics told a similar story about the most problematic tasks as well as the poor holistic experience. Although the section for inputing taxable income was the most critical, the entire user journey was marred by numerous slowers and stoppers.
Working with the client’s various teams, I organized and structured the content to make it easier for users to understand and scan the page.
Taxable Income Type
The original interface displayed 16 income types in an unordered vertical list. To reduce cognitive load, I organized them into 5 logical categories and prioritized by usage frequency. This made it easier for users to quickly find their income type.
Business Type Dropdown
The Other Sources of Income page originally featured an overwhelming 48-option dropdown, burying relevant choices in a sea of possibilities. I restructured it into 10 intuitive categories, turning a frustrating search into a faster, more scannable browsing experience.
Wireframes
I created Figma wireframes for the pages with the most ambiguity. To stay efficient within the tight timeline, I would move straight to high-fidelity UI for the remaining screens.
While there were several UI changes that I made, I'd like to emphasize a few key improvements that I implemented and the rationale behind my design thought process.
1. Selecting the correct Taxable Income Type
Before
Participants struggled to identify the correct income type due to a lack of clear structure and categorization. The interface displayed 16 options in an overwhelming vertical list. Additionally, the use of the green text as the CTA confused users, who often tried to click the disabled input field instead.
After
I replaced the misleading disabled inputs with a clear tertiary button system and repositioned labels to create a logical reading flow. The new design guides users naturally from left to right, with clickable elements that provide immediate visual cue on how to input their income amount.
2. Filling out Dividend Income detail
Before
Visual clutter and competing elements distracted users from the primary task. For example, the green-highlighted table misled users into thinking the checkboxes were interactive, although the intended action was to select a dividend type and input details. This led to unnecessary clicks and user hesitation.
After
I redesigned the dividend income page to feel visually separate from the main flow, reducing cognitive load. Key features were given prominence through clear button hierarchy. The Tax ID label was simplified, with added tooltips for clarity. Finally, I separated the data entry section from the summary table to streamline the experience.
3. Filling out the Other Income Sources detail
Before
The 48-option dropdown made selecting a business type overwhelming. Users were unsure whether amounts should be entered pre- or post-tax, and the "Cost of Goods Sold" checkbox caused confusion due to unclear purpose and placement.
After
Split the dropdown into main and subcategories to make business types easier to find. Added dynamic helper text to guide users on revenue thresholds and the correct "Cost of Goods Sold" method. Rewrote labels for clearer tax deduction and entry instructions.
Continuous UI refinement through rapid iterative testing
I tested our UI prototype with a total of 10 additional users, iterating on the design as soon as issues are discovered by one or two participants.
Final UI Screens and Prototype
In total, our team delivered over 40 core UI screens. I played a key role in designing many of them, overseeing the two primary tax filing flows—individual and married joint—to ensure a consistent, accessible experience across both.
I collaborated with the other designers on my team to create a robust Design System, developing documentation guidelines and defining components to ensure consistency of visual elements and interaction patterns.
Foundations
Without consistent design standards, the Thai Revenue Department's digital services look entirely different from one another, creating a fragmented user experience. These building blocks establish a unified visual language that applies across E-Filing and all other digital services.
Component Library
Many usability issues we uncovered stemmed from poorly implemented interactive patterns. Our component library solves these problems with user-friendly elements that ensure consistent, intuitive experiences while accelerating development.
