Tax Technology & Data Analytics

Leading tax data product strategy in regulated environments

Tax Technology Senior Manager at Vodafone Group, leading tax data product strategy for a Data & Analytics squad. I set priorities, shape delivery, and prototype in Python and SQL to prove value quickly, bridging product requirements with data models and code. Speaker at the ITR AI in Tax Forum and author at analytax.ai.

Lymington, UK · cjcharrison@gmail.com · analytax.ai
20+
Years in Tax & Tech
20+
Markets Covered
CTA
Chartered Tax Adviser
1st
BSc Physics, Exeter
What I Do

Tax Data Product Strategy

▼

Strategy, roadmaps, backlog prioritisation and stakeholder alignment across engineering, data, design and compliance.

  • Built the case for and secured a dedicated tax-focused D&A squad
  • Write epics, user stories and acceptance criteria; review data models and code
  • Prioritise backlogs and align delivery with D&A engineering squads
  • Drive adoption through stakeholder engagement, training and change management

Tax Reporting & Compliance

▼

Tax reporting, account statements, transaction exports, audit trails and controls in highly regulated, multi-market environments.

  • Involved across all aspects of the Group Tax reporting function
  • Compliance, risk management, management reporting and ad-hoc analysis
  • Multi-market regulatory frameworks and cross-border compliance
  • Transfer pricing documentation and tax authority responses

Data & Analytics

▼

Python, SQL, BigQuery, Streamlit dashboards, anomaly detection, ML classification, LLM integration and data warehousing on GCP.

  • Tax Risk Register — Streamlit app on GCP with BigQuery time-series data model and LLM-powered text-to-SQL querying via Gemini
  • VAT anomaly detection using Prophet-based forecasting in quarterly review cycles
  • Intelligent transaction classification — ML/LLM feasibility for automating tax-deductibility classification
  • Leading tax’s role in Vodafone’s Unified Semantic Layer (SAP Datasphere)
  • API integrations to extract data from third-party software

Vendor & Delivery

▼

Vendor evaluation, integration and management. Coordinating global teams, shared-services and Big 4 advisory relationships.

  • Led evaluation and integration of Alteryx, MS Power Platform
  • Managed vendor relationships and performance for reporting tooling
  • Coordinated VOIS shared services and external advisors (KPMG)
  • Global stakeholder management across 20+ markets
Career Timeline
Tax Technology Senior Manager
Vodafone Group Services, Newbury & London
Feb 2022 – Present ▼
Hands-on tax technology lead within Group Tax, working at the boundary between tax, finance and Group Data & Analytics. Defines tax data product strategy, prototypes solutions in Python/SQL, and partners with Group D&A to deliver them at scale.

Strategy & Squad

  • Built the case for a dedicated tax-focused D&A squad — after several years of proving value through pilots, secured senior sponsorship to formalise a dedicated squad of developers focused exclusively on tax
  • Leading tax’s role in the Unified Semantic Layer — identifying and prioritising tax datasets for D&A’s Unified Semantic Layer (SAP Datasphere), replacing duplicate static Excel extracts with live, governed, self-service access to consistent data
  • Involved across all aspects of Group Tax reporting — compliance, risk management, management reporting and ad-hoc analysis

Build & Deliver

  • Tax Risk Register (Streamlit on GCP) — designed and built a web application replacing a legacy SharePoint list used by ~100 tax staff across ~20 markets, with a time-stamped movement table in BigQuery and LLM-powered text-to-SQL querying via Gemini
  • Intelligent transaction classification — prototyped ML/LLM approach in Jupyter for automating tax-deductibility classification; currently in feasibility with D&A squad
  • VAT anomaly detection — Prophet-based forecasting tool for input and output VAT, used in quarterly review cycles to surface unexpected movements that rule-based controls miss
  • Delivered a tax data warehouse in Google BigQuery, consolidating data from SAP, HFM, Concur and other source systems for optimised storage, analysis and reporting (incl. CbCR and Pillar II)
  • Built multiple Streamlit dashboards for risk detection, anomaly identification and compliance monitoring
  • Integrated third-party software via APIs to extract and consolidate data into reporting pipelines
  • Analysis of large financial data sets using SQL, Python and Alteryx
  • Presentation of data and insights via dashboards in Power BI and Python

Adoption & Governance

  • Led vendor evaluation of automation tooling (Alteryx, MS Power Platform) for reporting and compliance workflows
  • Promoted change and a data-driven culture, embedding continuous learning across global tax teams
  • Hosted Vodafone’s Global Tax Conference themed on tax data management
  • Drove adoption across 20+ local markets through training, webinars and a community of advocates
  • Partnered with design to improve reporting UX across internal web applications
Speaker — ITR AI in Tax Forum, London
Main-stage speaker 2025; invited back 2026. 2026 talk: “From Rules to Models — How Data, Statistics and AI Are Reshaping Tax Analytics”
Launched analytax.ai blog
Tax technology, data analytics, machine learning and LLM applications in compliance and risk
Data Business Practitioner Level 2
Vodafone University ‘Love Data’ programme
International Tax Manager
Vodafone Global Enterprise, Newbury & London
Dec 2014 – Feb 2022 ▼
International tax business partner for Vodafone Business. Joined as Tax Solutions Analyst; progressed through compliance, risk and product advisory work. Began the move into data and technology in this period.

Business Partnering & Product Advisory

  • Partnered with product managers and commercial teams on the global rollout of new IoT, Cloud and Hosting products — translating tax and contracting requirements into deliverable product designs
  • Developed tax-efficient contracting models for new technical products
  • Reviewed cross-border commercial contracts and negotiations with enterprise customers and suppliers
  • Organised and chaired global tax webinars with tax teams across Vodafone Group and Local Markets
  • Delivered tax training to legal and commercial teams
  • Involved in graduate recruitment

Data, Risk & Technology

  • Built the first iteration of Vodafone’s global tax risk register on SharePoint with Power Automate workflows — the predecessor system that the current Streamlit/BigQuery product is replacing
  • Worked with Group BI and Analytics Product Managers to develop tools for data-driven tax risk monitoring
  • Automated CFC data gathering and calculations using Alteryx
  • Piloted automation and data-driven strategies aligned to Vodafone Tech 2025 ambition
  • Management of global tax risks and implementation of tax technology to monitor risk

Compliance & Reporting

  • Managed compliance, transfer pricing documentation and tax authority investigations across the European footprint, coordinating VOIS shared services and KPMG
  • Managed simultaneous compliance for legal entities across Vodafone Business’s European footprint with statutory deadlines
  • Internal tax reporting submissions and automation of provision calculations
  • Led R&D tax relief claims for innovative projects including Project Nucleus

M&A & Transactions

  • M&A due diligence and post-acquisition tax integration and restructuring
  • Involvement in transformational projects across the business
Corporate Tax Director
PKF Francis Clark, Poole
Jun – Oct 2017 ▼
Head of Corporate Tax across Poole, New Milton and Salisbury offices. Led the Innovation Taxes practice for the firm.
  • Head of Corporate Tax in Poole, New Milton and Salisbury
  • Head of and development of Innovation Taxes (R&D tax reliefs, Patent Box) for PKF Francis Clark
  • Corporate tax business development
  • Led a team of c.15 corporate tax specialists
R&D Tax Manager
Deloitte, Reading & London
Jan 2013 – Nov 2014 ▼
Project managed complex R&D tax relief claims for FTSE 250 and large corporate groups.
  • Project management of teams to prepare and deliver complex R&D tax relief claims for FTSE 250 groups
  • Complex analysis of large data sets to identify expenditure qualifying for tax relief
  • Business development activities targeting private markets in relation to R&D Expenditure Credits and Patent Box
  • Preparation and delivery of seminar presentations and webinars on R&D tax reliefs and Patent Box
  • Member of the Treasury R&D consultative committee; actively involved in government consultations on the R&D Expenditure Credit regime
  • Regular author of articles for the Tax Journal on R&D Expenditure Credits
  • Involved in Deloitte response to the Budget
Chartered Tax Adviser (CTA) — 2009
ATT with Commendation in Accounting — 2007
Tax Trainee → R&D Tax Manager
Grant Thornton, Poole → Southampton → Oxford
Apr 2005 – Dec 2012 ▼
Progressed from tax trainee to R&D Tax Manager over 7 years across three offices. Included a 5-month secondment at Ernst & Young.

R&D Tax Manager — Oxford (Nov 2007 – Dec 2012)

  • Member of the national R&D tax practice
  • Member of the Treasury R&D consultative committee; involved in government consultation on ATL tax credit
  • Member of core Patent Box team for Grant Thornton
  • Project management of large company R&D tax relief claims including FTSE 100 groups
  • Development of close working relationships with individuals across multiple group companies including group tax managers
  • Authored articles in the Tax Journal, most recently on FA 2012 R&D changes
  • Shortlisted in Lexis Nexis Taxation Awards for ‘best tax team’ in a large firm
  • Extensive use of Excel to analyse large data sets
  • Line management responsibilities

R&D Tax Specialist — Ernst & Young (Jun – Nov 2007)

  • Preparation of R&D Tax Relief claims for large Plc clients
  • Extensive data analysis and sampling methods to arrive at eligible expenditure
  • Preparation of technical reports to support claims

Assistant Manager, Tax Advisory — Southampton (2007)

  • Employer solutions and share schemes (EMI)
  • Capital gains tax planning — Entrepreneurs’ Relief, PPR, EIS
  • Inheritance tax planning — BPR, trusts, PETs
  • HMRC clearance applications, investigations and negotiations
  • Profit extraction — incorporation, reconstructions

Tax Trainee / Tax Senior — Poole (Apr 2005 – May 2007)

  • Preparation and submission of personal and corporate tax returns and computations
  • P11D preparation; trained new starters and placement students
  • Tax Software Champion
Published author — Tax Journal
Multiple articles on R&D tax reliefs and Patent Box
Research Scientist
BAE Systems Advanced Technology Centre, Bristol
Jan 2003 – Apr 2005 ▼
Research scientist in BAE’s experimental optics and laser group, working as a technical consultant to business units across the Corporation. Chairman’s Award for innovation; security clearance under the Official Secrets Act.
  • Acted as a Technical Consultant to business units within and outside the Corporation
  • Projects included using lasers to relieve residual stresses in friction stir welds
  • Generated innovative solutions and problem solving — received a Chairman’s Award for innovation
  • Planned and managed projects in conjunction with customers to a budget, monitoring and preparing interim status reports
  • Written reporting and oral presentation of solutions to high-profile defence clients
  • Security clearance to work on sensitive projects under the Official Secrets Act
  • Advanced use of Excel in modelling and analysing data
  • Collaborated with academic and government research partners
BSc (Hons) Physics — First Class
University of Exeter · 1999 – 2002
A-levels: Maths (A), Physics (B), Biology (C)
Woodroffe School, Lyme Regis · 1991 – 1999
Speaking, Writing & Technology

Speaking & Writing

ITR AI in Tax Forum

Main-stage speaker 2025; invited back 2026. 2026 talk: “From Rules to Models — How Data, Statistics and AI Are Reshaping Tax Analytics”.

analytax.ai

Ongoing blog on tax technology, data analytics, machine learning and LLM applications in compliance and risk.

Technology

Python pandas Prophet scikit-learn SQL BigQuery GCP Streamlit Dash / Flask Git REST APIs Alteryx Power BI Google Looker Power Platform SAP Datasphere Excel

Qualifications

Chartered Tax Adviser (CTA) — 2009 ATT with Commendation in Accounting — 2007
BSc (Hons) Physics, First Class University of Exeter
Data Business Practitioner Level 2 Vodafone University

Let’s Talk

Interested in tax technology, analytics or anything on the blog? I’d love to hear from you.

Get in Touch