Joanna Yap

Partner, Withers KhattarWong*

Withers KhattarWong LLP is a Singapore law practice, affiliated with Withers LLP.

Joanna is a partner in the private client and tax team.

She has more than 16 years of experience in advising all aspects of Singapore revenue law in particular income tax, goods and services tax, property tax, stamp duties and tax treaties with a proven track record of successfully resolving tax disputes for clients with the Inland Revenue Authority of Singapore. Prior to joining the firm 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 prosecution and hearings before tax tribunals and the Supreme Court as both legal counsel and co-counsel in landmark cases including Singapore’s first tax avoidance case. Apart from Singapore revenue law, Joanna also advises on succession planning, immigration, and probate and administration.

Secrétaire Alysson Hui Hua Chan


Joanna has an excellent understanding on legal issues at hand and is our preferred counsel for Singapore-related matters. Her highly personalized approach stands her apart from other legal counsels. She is professional and efficient and is certainly a pleasure to work with. I strongly recommend her services.


Worked closely with Joanna on several tax cases for UHNW families. She is professional and offers very objective advice even through it may not be easily digested, which is ultimately in best interest of families.


Joanna brings with her strong legal knowledge and many years of experience. She is personable, helpful and very professional. She always acts in the best interest of her clients and we can certainly count on her for quality advice. Feedback from our clients has also been a positive one. We would highly recommend Joanna for her service.






Zhao Hui Fang and others v Commissioner of Stamp Duties [2017] SGHC 105 in which she successfully represented the trustees of a charity purpose trust to obtain a refund of additional buyer’s stamp duty imposed by the Commissioner on the purchase of a residential property.

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.

Singapore, 2003

‘Goods and Services Tax’, The Law and Practice (2nd Edition), co-author

‘Chapter 24: Singapore’, The Tax Disputes and Litigation Review, co-author

‘Chapter 28: Singapore Income Tax’, Singapore Law Commentaries of Singapore Commercial Laws, co-author

The Law Society of Singapore

Singapore Academy of Law

Singapore Institute of Accredited Tax Professionals



  • English
  • Mandarin


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