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18 specialist services, grouped by business need.

One WONE Global Partner for each service in each market. Start from what you need to do, or go straight to a service.

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Named senior professionals, each admitted as the one firm for a service in their country, and the firms they lead.

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Sourced answers on doing business across borders.

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Answers come from statements checked against official sources, with the sources shown. Research, not advice.

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Situations · Common situations · Tax, finance & assurance

Tax assessments, disputes & management

Tax assessments, audits, penalties and refunds, at home or abroad. Usually for: companies, entrepreneurs, taxpayers.

18 common situations · 3 usually cross-border

Find the one closest to yours

Where a situation has its own page, it opens there. Otherwise, bring it to WONE Global with your question already filled in.

  1. We have received a major corporate tax assessment Full situation page →
  2. The tax authority has challenged our deductible expenses Bring this to WONE Global →
  3. Our business is under a VAT or GST investigation Full situation page →
  4. An overdue tax filing has triggered penalties Bring this to WONE Global →
  5. We need to contest an alleged permanent establishment Full situation page →
  6. A tax audit has begun in a foreign subsidiary Usually cross-border Full situation page →
  7. An asset sale has created an unexpected tax bill Bring this to WONE Global →
  8. We need to review the tax consequences of dividends Full situation page →
  9. A business owner faces a personal income tax reassessment Bring this to WONE Global →
  10. We want to settle a long-running tax dispute Bring this to WONE Global →
  11. An employee stock option plan has unexpected tax effects Bring this to WONE Global →
  12. We have an indirect tax refund stuck with the authorities Bring this to WONE Global →
  13. A foreign tax credit has been denied Usually cross-border Full situation page →
  14. We need to review withholding tax on royalties or services Full situation page →
  15. A tax authority has challenged the valuation of a transaction Bring this to WONE Global →
  16. We need recurring tax compliance across many subsidiaries Bring this to WONE Global →
  17. Our international payroll taxes do not reconcile Usually cross-border Bring this to WONE Global →
  18. A tax amnesty or disclosure opportunity requires evaluation Bring this to WONE Global →

First questions

What we will ask first

  1. 01Which authority, which tax and which years?
  2. 02What is the deadline to respond or appeal?
  3. 03What documents support your position?
  4. 04Could the issue affect other countries or years?

The approach

How WONE Global usually approaches it

  1. Step 1Read the assessment and the deadline.
  2. Step 2Prepare the response or appeal with a local tax professional.
  3. Step 3Negotiate or litigate where needed.
  4. Step 4Fix the cause so it does not recur.

What is needed varies by country and by matter. Your WONE Global professional confirms the work, timing and fees before anything starts.

Across borders

Complications to check

Issues to assess when more than one country is involved. They are prompts, not conclusions about any country's law.

  • Cross-border tax residenceExecutives or entities may be treated as resident in different jurisdictions
  • Permanent establishment riskEmployees or agents abroad may create local taxable presence
  • Transfer pricing scrutinyConnected companies trade under different documentation and valuation expectations
  • Court vs arbitration forumAgreement uses arbitration while assets and key witnesses are in different countries
  • Recognition of judgmentsA party wins abroad but needs lawful local recognition and enforcement

WONE Global Partners

Professionals who handle this work

Named professionals for these services. Where none is listed for your country, WONE Global names a vetted firm to you before any work starts, subject to availability and conflict checks.

Katherin Diaz VelillaBogotá · Colombia

WONE Global Capability Partner · Colombia

Katherin Diaz Velilla

Complete profile

Co-Founder · V&V Associates · Bogotá

International tax attorney and strategic advisor with 12+ years across Colombia's DIAN, Ministry of Finance, Senate, Presidency, and EY. Co-founder of V&V Asociados. Specializes in cross-border tax structuring, transfer…

Mauro Tejada RamonQuito · Ecuador

WONE Global Capability Partner · Ecuador

Mauro Tejada Ramon

Tax & Legal Partner · G&G Auditores Independientes & Lex Fiscal Corp · Quito

Professional with 20 years of experience in Tax Administration, performing functions in the managerial and tax administration fields. Experience related to the fiscal field in the main sectors of the economy: Banking, c…

Ulrike Berner, MBAMunich · Germany

WONE Global Capability Partner · Germany

Ulrike Berner, MBA

Managing Partner · BSP Berner Schaeffler & Partners GmbH · Munich

Ulrike Berner has been Managing Director and shareholder of BSP since 2021, leading the strategic direction, client relationships, and business development of the firm. She has extensive experience working with firms an…

Editorial examples of situations that arise, not a list of WONE Global clients or matters. The specialist area is a way to find your situation, not a separate practice group.

WONE Global Intelligence

Ask about doing business across borders

Ask in your own words. Answers come from WONE Global's checked records, with every source shown, and end with the named Partner who can act. Go deeper on any point, or build a decision file.

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