Joanna Yap


  • Education: University of Manchester, LL.B (Hons)
  • Admitted: Singapore, 2003
  • Languages spoken: English • Cantonese • Mandarin
  • Year joined: 2015
  • Year became partner: 2015


Joanna joined Withersworldwide in 2015, following the Formal Law Alliance (FLA) between Withers and Singapore law firm KhattarWong LLP. She is a partner of KhattarWong’s tax and private client practice group, focusing on revenue law and in resolving tax disputes with the Inland Revenue Authority of Singapore (IRAS).

Joanna has more than a decade of experience in advising all areas of Singapore taxation, in particular, income tax, goods and services tax, property tax, stamp duties and tax treaties. Prior to joining KhattarWong in 2014, Joanna was a Senior Legal Specialist with the IRAS where she advised the authority on complex and novel points of revenue law. She has also represented the authority in criminal prosecutions, and hearings before all tax tribunals and the Supreme Court as both lead counsel and co-counsel in landmark cases including Singapore’s first tax avoidance case.

Recently, she has been listed in the 2016 IFC Powerwomen Top 200 by Citywealth.    


  • AQQ v Comptroller of Income Tax [2011] SGITBR 1, AQQ v Comptroller of Income Tax [2013] 1 SLR 1361 and Comptroller of Income Tax v AQQ and another appeal [2014] SGCA 15 in which she successfully represented the Comptroller who has invoked Singapore's general anti-avoidance provision on a corporate restructuring and financing arrangement
  • AVD v Comptroller of Income Tax [2011] SGITBR 3 in which she represented the Comptroller on the waiver of shareholder's test and the carrying forward of unutilised losses
  • HSBC Institutional Trust Services (S) Ltd v Chief Assessor [2011] SGVRB 1, Chief Assessor v HSBC Institutional Trust Services (Singapore) Ltd [2012] 3 SLR 933 and HSBC Institutional Trust Services (Singapore) Ltd v Comptroller of Income Tax [2013] 2 SLR 173 in which she successfully represented the Chief Assessor to deviate from established case law to hold that depreciation of asset items is to be included in the annual value of a property

Publications and speaking engagements


  • The Law Society of Singapore
  • Singapore Academy of Law
  • Singapore Institute of Accredited Tax Professionals

On a personal note

Joanna enjoys travelling and photography.

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