Web Application

QuixMTD

The only 100% agnostic MTD bridging software on the market. No accounting knowledge required. Upload your messy spreadsheet with rough descriptions and we automatically categorise everything into the correct HMRC boxes, validate the data, and submit your income tax return directly.

Go to QuixMTD

ReactExpressHMRC APIOAuth 2.0PostgreSQL

Overview

About the Project

Every other Making Tax Digital solution requires users to pre-categorise transactions, understand accounting terminology, and map expenses to specific HMRC boxes. QuixMTD takes a completely different approach. It's the only fully agnostic bridging software on the market. Users upload their existing spreadsheets with rough descriptions like "boiler repair" or "Screwfix", and the system automatically categorises everything into the correct HMRC boxes.

The technical challenge was building an intelligent categorisation engine integrated with HMRC's OAuth 2.0 authentication flow and MTD submission APIs. The entire pipeline, from spreadsheet parsing and fuzzy-matching categorisation to validation and direct HMRC submission, was built to require zero accounting knowledge from the end user.

Features

Key Functionality

Smart Categorisation
Automatically maps rough transaction descriptions to the correct HMRC income tax categories. No accounting knowledge needed.
Spreadsheet Ingestion
Parses messy, real-world spreadsheets with flexible column detection and data normalisation.
HMRC API Integration
Full OAuth 2.0 flow with HMRC's MTD APIs for secure, direct income tax return submission.
Confirm & Submit
Users review auto-categorised transactions and confirm before submission. The entire flow takes minutes.
Submission History
Complete audit trail of all past submissions with status tracking and HMRC receipt references.
Secure Authentication
Government-grade OAuth 2.0 authentication protecting sensitive taxpayer data throughout.

Smart Categorisation
Automatically maps rough transaction descriptions to the correct HMRC income tax categories. No accounting knowledge needed.
Spreadsheet Ingestion
Parses messy, real-world spreadsheets with flexible column detection and data normalisation.
HMRC API Integration
Full OAuth 2.0 flow with HMRC's MTD APIs for secure, direct income tax return submission.
Confirm & Submit
Users review auto-categorised transactions and confirm before submission. The entire flow takes minutes.
Submission History
Complete audit trail of all past submissions with status tracking and HMRC receipt references.
Secure Authentication
Government-grade OAuth 2.0 authentication protecting sensitive taxpayer data throughout.

Reflection

What I Learned

01Designing an intelligent categorisation system that handles ambiguous, real-world input data.

02Implementing OAuth 2.0 authentication flows with government APIs and handling token refresh cycles.

03Building robust spreadsheet parsing that gracefully handles inconsistent formats and missing data.

04Creating interfaces that abstract away complexity, making a regulation-heavy process feel effortless.

05Structuring a full submission pipeline with rollback handling and error recovery at each stage.

06Writing comprehensive test suites for financial data transformations where accuracy is critical.

07Designing audit logging systems to maintain a clear trail of all submissions and modifications.

08Building rate-limited API integrations that respect third-party service constraints without blocking the user.

09Managing complex date-range queries across overlapping tax periods and financial quarters.

10Architecting a modular plugin system so new HMRC obligation types can be added without touching core logic.