CNF Checker

A step-by-step form application that helps users determine whether a Claim Notification Form (CNF) is necessary for HMRC R&D tax relief and what the submission deadline is.

Purpose

This application allows users to:

• Check CNF requirements based on company accounting periods
• Determine submission deadlines
• Receive guidance through the process

The tool is completely unauthenticated and available for anyone to use.

Technical Stack

• Frontend: HTML, TypeScript, CSS using Svelte framework
• Build Tool: Vite
• Styling: TailwindCSS
• Deployment: AWS CDK, S3 bucket for hosting
• External APIs: Companies House API for accounting period data

Development Setup

1. Clone the repository
2. Install dependencies:

   npm install
   

3. Create a .env file in the project root with:

   VITE_CH_API_KEY=your_companies_house_api_key
   

4. Start the development server:

   npm run dev
   

Deployment

The application is deployed using AWS CDK to an S3 bucket configured for static website hosting.

Main Environments

• dev: Development environment
• prod: Production environment

Custom Deployment

Deploy to any named environment using:

./deploy/deploy.sh <environment_name>

This script:

1. Builds the application
2. Deploys the infrastructure using CDK
3. Uploads the build files to the S3 bucket

Application Flow

The application guides users through a series of questions to determine CNF requirements:

1. Enter company number (fetches data from Companies House API)
2. Select accounting period
3. Answer questions about R&D tax relief claims
4. Receive result indicating if CNF is required and the deadline