HMRC Interaction Design
Designing user-centred government services using HTML prototyping and the GOV.UK Design System
About This Role
As an Interaction Designer at HMRC, I design user-centred government services following the Government Digital Service (GDS) standards. My work focuses on creating accessible, intuitive interactions that help citizens complete tasks efficiently while meeting strict accessibility and usability requirements.
I primarily use GOV.UK Design System components, only deviating where user research or service needs clearly justify it. Using HTML prototypes allows me to share realistic artefacts with researchers, developers and stakeholders, and prototype at the same fidelity the service will be built in.
Note: This work is ongoing, and due to the nature of government services, final artefacts cannot be shared publicly. This case study demonstrates my approach, process and methods, particularly my use of UCD and HTML prototyping in a complex public-sector environment.
My Design Process
User-Centred Design (UCD) Led Approach
Understanding the Problem Space
I begin by building a strong understanding of the user problem we are trying to solve, the service context including policy, technical and operational constraints, and existing evidence from previous research and live services.
- Reviewing research findings, service documentation and existing journeys
- Working closely with user researchers, product managers, developers and content designers
- Helping shape problem statements that balance organisational needs with genuine user pain points
UCD Principle: Design starts with understanding users, not designing screens.
User Needs & Research Collaboration
User needs underpin every design decision I make. I work closely with User Researchers to understand key user groups, including users with low digital confidence or accessibility needs.
- Translate research insights into clear, testable design hypotheses
- Challenge assumptions and reduce solution bias early
- Observe or participate in research sessions
- Use findings to directly inform interaction choices and flow decisions
UCD Principle: Design should respond to evidence, not opinion.
Interaction Design & Prototyping (HTML-First)
Once user needs and journeys are defined, I move into interaction design using code-based prototyping. I design and iterate solutions using the HMRC Prototyping Toolkit.
- Mapping end-to-end user journeys and task flows
- Designing interactions that minimise cognitive load and error
- Building prototypes in HTML using the HMRC Prototyping Toolkit
- Accurately reflect how the service will behave in real use
- Test content, interaction patterns and accessibility together
UCD Principle: Prototype behaviour, not just layout.
Accessibility & Inclusive Design
Accessibility is treated as integral, not a separate step. Building prototypes in HTML helps ensure accessibility considerations are designed and tested early, rather than retrofitted later.
- Clear information hierarchy and plain language
- Predictable navigation and user flows
- Designing for keyboard, screen reader and assistive technology use from the outset
UCD Principle: Design for everyone, especially users with the greatest barriers.
Testing, Feedback & Iteration
Designs are continuously refined based on user research findings, team feedback and technical input, and observed usability issues in prototypes.
- Iterate or discard designs where evidence shows they are not meeting user needs
- Document decisions clearly so changes are transparent and grounded in evidence
UCD Principle: Iteration is a sign of learning, not failure.
Collaboration & Delivery
As an Interaction Designer, I work closely across disciplines to ensure designs are clear, feasible and user-focused.
- Product Managers to align designs with service outcomes
- Content Designers to ensure content and interaction work together
- Developers to ensure prototypes are buildable and accurately understood
UCD Principle: Shared understanding leads to better services.