HMRC Making Tax Digital
Compatibility Statement

Software: no~bull books v1.0 · Provider: Edward Jenkins t/a no~bull consulting · Date: 6 April 2026 · MTD Scheme: VAT · API: HMRC MTD VAT API v1.0

1. Software Overview

no~bull books is a cloud-based accounting application built on Google Apps Script, designed for UK sole traders and small businesses. It integrates with HMRC's Making Tax Digital (MTD) for VAT API to enable compliant digital VAT record-keeping and electronic submission of VAT returns.

2. MTD VAT API Functionality

API Endpoint	Status
GET /organisations/vat/{vrn}/obligations	✓ Implemented & tested
POST /organisations/vat/{vrn}/returns	✓ Implemented & tested
GET /organisations/vat/{vrn}/liabilities	✓ Implemented & tested
GET /organisations/vat/{vrn}/payments	✓ Implemented & tested
OAuth 2.0 authorisation flow	✓ Implemented & tested

3. Digital Record Keeping

no~bull books maintains digital records as required by MTD for VAT, including all nine VAT return boxes, business name and VAT registration number, and VAT accounting period dates. All records are stored digitally from point of creation in the user's own Google Sheets spreadsheet.

4. Fraud Prevention Headers

no~bull books submits the following fraud prevention headers with all MTD API calls, using the WEB_APP_VIA_SERVER connection method:

• Gov-Client-Connection-Method: WEB_APP_VIA_SERVER
• Gov-Vendor-Version: no-bull-books=1.0.0
• Gov-Client-Timezone — collected from user's browser
• Gov-Client-Browser-JS-User-Agent — collected from user's browser
• Gov-Client-Device-ID — persistent UUID stored in browser localStorage
• Gov-Client-User-IDs — Google account identifier
• Gov-Client-Screens — screen dimensions from user's browser
• Gov-Client-Window-Size — window dimensions from user's browser

Note: As a Google Apps Script application, the server-side public IP address is not directly accessible. We have disclosed this limitation to HMRC and are committed to implementing additional headers as guidance for cloud-hosted applications evolves.

5. Sandbox Testing Summary

Test Scenario	Result
OAuth 2.0 authorisation flow	✓ Pass
Retrieve VAT obligations	✓ Pass
Calculate VAT return (boxes 1-9)	✓ Pass
Save VAT return as draft	✓ Pass
Submit VAT return to HMRC	✓ Pass
Retrieve VAT liabilities	✓ Pass
Retrieve VAT payments	✓ Pass
Handle expired token	✓ Pass
Handle invalid date range	✓ Pass

6. Declaration

We confirm that no~bull books has been designed and tested to meet the requirements of HMRC's Making Tax Digital for VAT programme. We are committed to maintaining compatibility as HMRC's API and requirements evolve.

Signed
Name	Edward Jenkins
Role	Sole proprietor, no~bull consulting
Date	6 April 2026
Email	edward@nobull.consulting