The IFLR 1000: The Guide to the World's Leading Financial Law Firms
Capital Markets 2024/2025 – Expert Consultant for 3 consecutive years
Previously Highly regarded for 5 consecutive years
Previously Leading Lawyer for 7 consecutive years from 2011 to 2017
A client commended Boon Ann as a "top notch" lawyer who does "overall excellent work."
The Asia Pacific Legal 500
Capital Markets 2022 – Recommended lawyer for 4 consecutive years, Leading Individual for 13 consecutive years from 2006 to 2018
Projects & Energy 2017 – Recommended lawyer
A client commended him for his “maturity and experience.”
"Knowledgeable", "gets straight to the point" and "refreshingly solutions-oriented’"
“…he is an ethical and learned expert who is better at transpositional consideration, listening and communication. Most of our projects are major and complex. When a project encounters difficulties, he often advances despite difficulties and proposes a solution that is bright and effective. More importantly, he often gives us more understanding and encouragement when encountering difficulties. He is a friend that I and our entire team respect very much.”
“[Makes] time for us when we need them.”
He “[has] been there as steady as a lighthouse on a cape to guide us all these years on how to best liaise with and operate within the Listco requirements.”
Best Lawyers International: Singapore
Capital Markets Law 2025 – Endorsed individual for 14 consecutive years
Corporate Law 2025 – Endorsed individual for 8 consecutive years
Chambers Asia-Pacific and Global
Capital Markets 2019 – Leading lawyer for 9 consecutive years
"He's a good lawyer – that's a given – but also very well attuned to the regulatory nuances."
"We can trust wholeheartedly all our problems to him and know he'll come up with solutions."
"Someone I would rely on in a difficult situation”
"Articulate and intelligent, and the quality of work is always very good."
Who's Who Legal
National Guide: Southeast Asia - M&A and Governance 2024 - Recommended Lawyer
Mergers & Acquisitions 2016 - Leading Lawyer
Capital Markets 2013 – Leading Lawyer for 2 consecutive years
Asialaw Leading Lawyers
Capital Markets 2014 – Leading Lawyer
Practical Law Company Which Lawyer?
Capital Markets 2012 – Endorsed for 3 consecutive years
The IFLR 1000: The Guide to the World's Leading Financial Law Firms 2011 notes that clients "have good working rapport with Sin Boon Ann in dealing with transactional issues and regulatory issues," and cited him as being "dynamic in terms of pitching for deals. His approach to legal issues is commercial, yet he is aware of regulatory concerns. He'll think out of the box for ideas for our clients."