Bringing Tax filing to everyone:
A new self-service Web Application
DIAN
P R O D U C T S T R A T E G Y /
V I S U A L H I E R A R C H Y /
T A S K A N A L Y S I S /
U X R E S E A R C H /
R O A D M A P P I N G
A parallel product designed to open access to a broader audience enabling individuals with no accounting knowledge to file taxes independently, while preserving the existing workflow for experts. Colombian tax system.
CONTEXT
In Colombia, individual income tax filing is regulated by the national tax authority, DIAN (Dirección de Impuestos y Aduanas Nacionales), through the official Form 210. Only certain individuals are required to file annually, based on criteria such as total assets, gross income, credit card transactions, bank deposits, or VAT (IVA) responsibility.
Filing deadlines are seasonal (typically between August and October) and require strict adherence, which directly influenced our project timelines. For the 2021 tax year (filed in 2022), around 4.45 million individuals filed; for 2022 (filed in 2023), the number rose to approximately 5.44 million.
AS-IS / INITIAL STATE:
Before we joined, most non-expert individuals relied on accountants who managed the process through spreadsheets and bespoke tools.For anyone attempting the process alone, the experience was complex.
While the official Form 210 ensured legal compliance, it was not designed for self-service. As a result, people without accounting knowledge faced:
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Confusion about eligibility and filing rules
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Dependence on costly professional help
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Limited access to accurate, timely filing
The system served experts, but excluded everyday taxpayers seeking a simpler, guided path.
CHALLENGE:
The initial ambition was to modernize Colombia’s tax-filing system by replacing the outdated, accountant-centric approach with a unified digital route. Early research revealed a key gap: while experts were already equipped, everyday taxpayers lacked both guidance and confidence to file independently.
The design challenge evolved into:
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Empowering non-experts to file confidently via self-service.
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Translating complex legal and financial structures into clear, human-centred flows.
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Ensuring full regulatory compliance within a tight annual filing window.
Balancing the depth of official requirements with the simplicity expected of modern digital services.
The goal was modernization and making it truly accessible to everyone
Team:
Katherine Moreno (Product Designer)
At a cross-level: DIAN Director Luis Carlos Reyes, legal team, Scrum team, stakeholders
BENCHMARKING & INSIGHTS
I analyzed how leading countries enable citizens to file income taxes online, trough a comparative review of high-adoption tax platforms, focusing on usability patterns, interaction models, and tone of communication.
The goal was to identify proven approaches that make complex government processes feel transparent, simple, and trustworthy for every user, selecting systems recognized for their broad digital adoption and strong citizen experience.
KEY REFERENCES:
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UK - HMRC Self Assessment: grouped questions by category and strong progress feedback improved completion rates.
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Netherlands - Belastingdienst: pre-filled data and clear section summaries built trust and reduced input burden.
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Estonia - E-Tax Board: one-click submissions and tailored segmentation (citizen vs entrepreneur) maximised adoption.
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USA - IRS Free File & Partner Software: guided vs advanced modes introduced early dual-path design (inspiration for our expert/non-expert flows).
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Privates: They serve as inspiration for ideas and UX design patterns: personalization, progress bars, guided flows.
TAKEAWAYS:
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Group related questions into thematic sections rather than linear screens.
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Provide visual feedback on progress to improve clarity and user confidence.
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Segment users by skill level and deliver tailored experiences (expert vs non-expert).
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Batch input capability for repeatable data (assets, properties) further reduces effort.
DESIGN STRATEGY
PRODUCT DECISION: EXPERT vs NON EXPERT
I proposed two parallel paths:
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Expert Flow: Preserving the complete Form 210 structure for accountants and advanced filers, retaining access to the full Form 210 structure and advanced input fields.
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Non-Expert Flow: A guided, self-service experience for individuals without accounting knowledge. Features included simplified language, grouped thematic sections (assets, vehicles, income), visual progress status and a batch-entry table for vehicles/properties.
Due to delivery constraints and target impact, we focused primarily on the non-expert flow.
Accountants, being already proficient, continued to use their established workflows, while we addressed the broader gap: enabling regular citizens to file independently. This pragmatic prioritization maximized reach while maintaining compliance integrity.
TECHNICAL CONTEXT:
When I joined, engineering had produced a linear architectural prototype - essentially wireframes mapping 12-18 sequential steps aligned with the legal form structure. It wasn’t a usable UI yet, but an architectural map of the backend logic.
Our challenge: build usability and visual design on top of that architecture, without breaking the required legal data flow.
DESIGN PROPOSAL
The proposed solution was a clustered, modular structure of 6 thematic groups. Each cluster represented a mental model (e.g., My Data, My Income, My Assets, My Debts, My Benefits, My Tax).
VALIDATION PROCESS
Validation & A/B Testing — In-situ Sessions at DIAN
To validate our navigation models and observe real user behavior, we conducted a single in-person testing session at DIAN’s facilities.
This session combined two goals: verifying the preferred structure (linear vs. grouped flow) and gathering qualitative feedback on overall clarity, usability, and comprehension.
Early heuristic and mental-model analyses indicated that a fully linear flow would cause cognitive overload.
Given time constraints, we initially built within the prescribed architecture, but we documented our hypothesis and prepared an A/B test.
A/B Validation Setup
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Variant A (Clusters): A restructured flow with 6 grouped sections, contextual sub-questions, visual progress, and batch entry for repeatable data (e.g., vehicles, properties).
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Variant B (Form): The 14-step sequential flow with more questions inside (as per the engineering prototype).
Setup & participants
Sample size: 14 participants
Composition: 8 citizens (non-experts), 6 accounting professionals
Method: Moderated testing + DIAN sandbox environment
Focus: A/B TEST + Depth of understanding and flow behavior rather than large-scale statistical measurement.
Two structural prototypes were tested:
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Version A – Linear flow (14 consecutive screens)
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Version B – Grouped flow (6 thematic clusters / 14 substeps)
Participants were invited to the DIAN office and completed the test on-site using prototype versions of the platform.
Although we already suspected this outcome, we needed to validate it with concrete evidence before presenting to stakeholders. The immediate goal was to observe real people working with a realistic declaration scenario, collect rich data, and conduct the deep evaluation of the proposed solution right away to guide refinements.
Results clearly favored Variant A: users completed tasks faster, understood more, and reported lower frustration.
Test scenario (realistic data)
Each participant received the same plausible tax profile to complete key sections of the form. Example case given to participants:
Two properties: one fully paid, one currently under mortgage. First property rented out (rental income reported). Monthly salary income, a small amount of interest from savings, and a handful of deductible expenses (e.g., healthcare receipts).
This scenario intentionally included mixed complexity so we could observe how people handle multiple asset types, income sources, and deductions.
What we measured (qualitative + simple quantitative)
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Completion and navigation confidence
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Perceived clarity of structure (understanding of where they were and what was missing)
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Cognitive effort (hesitation, requests for help, signs of overload)
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Qualitative insights (verbal feedback, observed friction points)
Key findings & how they informed design
The grouped structure proved superior across all metrics:
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40% higher completion rate
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30% faster average completion time
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Participants reported clearer understanding of their progress
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Lower cognitive load due to thematic grouping and contextual explanations
Users in the grouped version felt more in control and found it easier to locate missing data or return later to incomplete sections.
Outcome
This data-backed approach enabled stakeholder buy-in to adopt the new structure for the non-expert experience.
The insights led us to adopt the clustered flow as the foundation for the final design. It balanced simplicity and structure, aligning with
how taxpayers mentally organize their financial data.The recorded sessions also informed microcopy, iconography, and help-text adjustments for the public release.
NEXT STEPS & PRODUCT EVOLUTION
From Validation to Iteration
The team entered a refinement phase focused on technical feasibility, regulatory compliance, and content accuracy.
The validated design was translated into a live, production-ready interface and became the foundation for the official DIAN income tax filing platform for individuals.
Once launched, we closely monitored behavior, feedback, and recurring pain points from both taxpayers and internal support teams.
2024 Release, extending the service beyond filing
Following the 2023 filing cycle, we identified a recurring friction point among users: uncertainty about whether they were required to file a tax return at all. Previously, citizens had to manually cross-check thresholds and legal criteria from the official regulation — a process that was confusing, time consuming, and error-prone.
To address this, we proposed to design a “Check if you need to file” feature in 2024, a simple web form that connects to DIAN’s data services.
By entering their national ID and personal data, citizens instantly receive:
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A clear confirmation of whether they must file
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A direct link to start the declaration process
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The personalized filing deadline date
This feature reduced confusion and support center calls, helping users start their process with greater confidence and clarity.
ITERATION APPROACH
The project began in May 2023 and launched in September, aligned with the annual filing season. In the following months, the team refined the product based on user feedback and regulatory updates.
By the end of 2023, about 8% of total filers used the non-expert flow. In 2024, adoption increased to an estimated 12–20% (≈1.5M users), confirming its impact and scalability. Adoption Growth: 2023 → 8% | 2024 → 12–20%
A new iteration for 2024 focused on stability, clarity, security, and traceability, following a seasonal, continuous improvement model that kept the product aligned with both citizen needs and regulatory standards.