Freelance tax technology
Wouter Maes
Indirect Tax Technology Consultant
I design and implement solutions for indirect tax and local legal requirements (“localizations”) within SAP ECC and S/4HANA. In practice that means making VAT and withholding tax logic add up in countries that each have their own rules and their own exceptions. I co-led the largest Vertex implementation in Europe, covering more than 60 countries, and led tax engine projects with Vertex and Thomson Reuters for multinationals such as LEGO, Agfa and Sibelco.
- Indirect tax and localizations within SAP ECC and S/4HANA
- Co-led the largest Vertex implementation in Europe (60+ countries)
- Law degree with a tax major (KU Leuven), 8 years at Deloitte and Lenovo
Limburg, Belgium - active across Europe
Career
Where the experience comes from
Years between the tax department and the SAP team, enough to speak both languages, and to know where they talk past each other.
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2026–present
Freelance Indirect Tax Technology Consultant
Frametech · Belgium · international
Independent consultant in indirect tax technology: tax engines, e-invoicing and localizations within SAP.
- US tax engine and global e-invoicing specialist for a 70B+ pharmaceutical multinational
- Ad hoc indirect tax technology support
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2023–2026
Manager Indirect Tax Technology Consulting
Deloitte · Belgium
Offering lead for indirect tax determination solutions, with a deep specialisation in global tax engine implementations with Vertex and Thomson Reuters.
- Co-led the largest Vertex implementation in Europe (60+ countries) within a broader S/4HANA transformation (Hitachi)
- Co-led the global Vertex implementation for LEGO
- Led a Vertex implementation in S/4HANA Public Cloud in the US (Agfa)
- Led the US and Canada implementation of Thomson Reuters ONESOURCE (Sibelco)
- Led two native S/4HANA implementations of Canadian taxes (Agfa)
- Design and strategy workshops on e-invoicing and e-reporting in 25+ countries for Fortune 100 companies (Nike, Synopsys, Chevron, Toyota)
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2022–2023
Senior EMEA Indirect Tax Specialist, Tax Technology
Lenovo · EMEA
EMEA S/4HANA tax transformation: designed tax solutions across 35+ jurisdictions.
- Moved from native VAT/GST determination to third-party tax engines (Vertex O Series and CFA, ONESOURCE)
- Led and designed the tax solutions for the EMEA-wide B2C and B2B e-commerce roll-out
- Created a long-term blueprint of EMEA tax requirements and solutions
- Managed the ERP tax impact of new service models (DaaS, EaaS, XaaS)
- Received the Lenovo WW Tax Executive Award for FY 2022
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2018–2022
Senior Consultant Indirect Tax & Tax Management
Deloitte · Belgium
Compliance, advisory and SAP services in indirect tax, within global SAP transformations in automotive, pharma, mining and glass recycling, and fashion retail.
- Automatic tax code determination (VAT, sales tax, other taxes and duties) across SD, MM and FI (Ardo, Sibelco)
- System-integrated B2B and B2G e-invoicing and (near) real-time reporting
- Local legal and tax reporting: VAT returns, listings, audit journals, Intrastat and SAF-T
- Native withholding tax in S/4HANA
- Global template design, tax workshops, ITC/UAT and handover to support teams
- Experience in 50+ countries from an e-invoicing and indirect tax technology perspective
Skills
Platforms, systems and tax matters
Tax engines
- Vertex O Series
- Vertex Accelerator+
- ONESOURCE Determination
- GlobalNext
- Rate & rule maintenance
SAP
- S/4HANA
- S/4HANA Public Cloud
- ECC
- SD, MM & FI
- DRC
- eDocument framework
- Condition technique
Compliance & reporting
- E-invoicing
- E-reporting
- Peppol
- SAF-T
- Intrastat
- ViDA
- Statutory reporting
Tax matters
- Indirect tax / VAT
- US sales & use tax
- Canadian GST/HST/PST
- Withholding tax
- Place of supply
- Chain transactions
- Reverse charge
Certifications & awards
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Vertex Tax Engine Implementation Certificate
2021
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Lenovo WW Tax Executive Award, FY 2022 (individual)
2023
Education
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Master’s degree in Law, major in Tax and Economic Law
KU Leuven · 2018
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Summer course International Taxation and Macroeconomics
University of Oxford · 2016
Languages
- Dutch Native
- English Fluent
- French Good knowledge
An assignment in mind?
Briefly send me your context: which SAP landscape, which countries, which deadline. Within one working day you get an honest answer about feasibility and availability.