Global Tax Management
Corporate tax services firm supporting mid-sized and large companies with tax accounting, compliance, automation and co-sourced tax operations.
- Highest 2026 tier: Tier II
- Corporate tax services and technology firm
- Corporate Tax Advisory
Overview
Global Tax Management, commonly branded GTM Tax, was founded in 1995 to support corporate tax departments. It works with companies that need specialist capacity, recurring operating support or modernization of tax processes.
Services include tax accounting and provision, income-tax compliance, international tax, state and local tax, indirect tax, transfer pricing, credits and incentives, automation, outsourcing and co-sourcing. GTM also participates in the WTS Global network.
Global Tax Management is included in one 2026 Advisory Ranking category. The highest recorded classification is Tier II.
Firm facts
| Legal name | Global Tax Management, Inc. |
| Founded | 1995 |
| Firm type | Corporate tax services and technology firm |
| Principal offices | Wayne, New York City, Pittsburgh, Cincinnati, Washington, D.C. |
| Primary focus | Tax accounting, compliance and department operations |
| Chief Executive Officer and Executive Director | David Sekula |
| Highest 2026 Advisory Ranking tier | Tier II |
Principal activities
Corporate tax advisory
Tax planning, structuring, compliance coordination and support for corporate tax departments.
International and transaction tax
Cross-border planning, transaction support, transfer pricing and ownership-structure analysis.
Tax operations and incentives
Tax accounting, provision support, credits, incentives, indirect tax and technology-enabled processes.
Global Tax Management works with clients on assignments that may combine strategy, specialist analysis, implementation support and organizational adoption. The precise scope depends on the mandate, sector, geography and client requirements.
Sector and mandate coverage
Sector coverage
- Corporate and private businesses
- Technology
- Manufacturing
- Financial services
- Real estate
- Consumer markets
Tax and mandate types
- Corporate tax planning
- International tax
- Transaction tax
- Tax accounting and provision
- State and local tax
- Credits and incentives
Market position
Global Tax Management is positioned as a corporate tax services and technology firm. Its relevance reflects the depth of its tax specialization, corporate-client orientation, technical delivery model and ability to support complex or recurring tax requirements.
Distinctive focus: Direct alignment with the recurring technical, staffing and technology needs of in-house corporate tax functions.
Competitive context
Global Tax Management competes with tax-led professional-services firms, independent accounting networks, specialist consultancies and tax-technology platforms. The relevant peer set varies by jurisdiction, client size, tax type and whether the mandate requires strategic advice, compliance execution, specialist documentation or software.
Comparable firms are selected according to overlap in business model, client segment, service coverage, geographic activity and mandate profile. Inclusion does not imply equivalence in scale, ranking or market position.
Leadership
| Person | Current position | Institutional background |
|---|---|---|
| David Sekula | Chief Executive Officer and Executive Director | Corporate tax services and firm leadership |
| John Diamond | Managing Director and Chief Operations Officer | Operations and New York metropolitan leadership |
| Ryan Lynch | Managing Director and Chief Growth Officer | Growth strategy and client development |
Leadership information reflects the public sources reviewed for this profile. View the firm’s website ↗
Corporate and regulatory information
Global Tax Management provides tax, accounting, advisory or tax-technology services. The precise professional and regulatory framework depends on the contracting entity, jurisdiction and engagement scope.
View registered-entity details
| Principal entity | Global Tax Management, Inc. |
| Professional status | Service- and jurisdiction-specific |
| Headquarters | Wayne, Pennsylvania |
| Primary jurisdiction | United States |
Principal offices
- Wayne
- New York City
- Pittsburgh
- Cincinnati
- Washington, D.C.
Rankings and recognition
Ranking inclusion is editorially determined. The existence or maintenance of a Wiki profile does not influence ranking eligibility, tier or position.
Related Economy analysis
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- Middle-Market Private Equity: Returns, Scale and Manager Selection
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- The Silent Reshuffle of the Advisory Market
Related institutions and subjects
Sources and data transparency
The profile is based on the following publicly available institutional, regulatory and editorial sources:
- Corporate Tax Services — corporate tax, specialty tax or tax-technology capabilities.
- Global Tax Management — firm overview, services and institutional information.
- Advisory Ranking — Top 30 Corporate Tax Advisory 2026 — inclusion and tier classification.
