Partner

Sarah Busca Bonvin

Attorney at Law | Co-Head of Tax Practice Group | Certified Tax Expert

Languages

French
English
Italian

Social media

Sarah Busca Bonvin is a lawyer specializing in tax law for both legal entities and individuals. In collaboration with Andrio Orler, she is responsible for CMS' tax department in Geneva, which she joined in 2017.

Certified as tax expert, she worked for 15 years as Director of Tax Affairs, particularly handling tax rulings, before being appointed Deputy Director General of the Geneva Tax Administration in 2010. Her roles within the Geneva Tax Administration allowed her to gain extensive experience and expertise in various areas of taxation.

Sarah Busca Bonvin regularly teaches in the LL.M. Tax program at the University of Geneva about the topics of corporate taxation and transfer pricing, as well as in the training program for tax experts (corporate taxation).

Publications

"La vente immobilière en viager: aspects de droit de droit civil et principales conséquences fiscales", in Not@lex 1/20: la revue de droit privé et fiscal du patrimoine

Memberships & Roles

Member of the Geneva Section of the Tax Expert Association (OREF)
Member of the IFA (International Fiscal Association)

Awards & Rankings

The Best Lawyers 2026 | Recognized in The Best Lawyers in Switzerland 2026 for Tax Law

Lectures list

Conference CMS Talks – "Fondation : évolutions récentes et en jeux pratiques", november 11 2025
OREF Seminar - ‘From investor to investment’ - Taxation of wealth in the case of indirect ownership, October 5, 2023
UNIL - ‘The arm's length principle in Swiss corporate tax law - Benefit attribution: triangle theory versus direct beneficiary theory, March 23, 2023
AGDA Seminar, FER Geneva - Classical foundations under Swiss private law, tax considerations, March 1, 2023
Introduction of the trust in Swiss law: civil and tax law perspectives, Société genevoise de droit et de législation (SGDL), 13 June 2022
Wealth Planning Perspectives - Planification patrimoniale franco-suisse, Banque Lombard Odier & Cie SA, 24 March 2022
Actualités en matière d'imposition à la source, L'imposition à la source des travailleurs, ISIS, November 2020
Journée de droit fiscal, Exposé de jurisprudence, OREF/University of Geneva, February 2020
La fiscalité de la philanthropie, L'exonération des entités poursuivant un but d'utilité publique ou de service public, ISIS, November 2019
Accompagner la clientèle francophone dans la mobilité internationale, LODH, November 2019
Post BEPS intellectual property taxation in Europe, CMS Tax Conference, Paris, January 31st 2019
CMS Talks | 5 perspectives sur le trust (fiscal aspects), Hôtel Mandarin Oriental, Geneva, November 20th 2018
Aperçu de la mise en oeuvre de la RFFA par les cantons, International Fiscal Association (IFA) Suisse, November 2018
Spontaneous Exchange of rulings – The post-BEPS World, University of Lausanne, October 2016
Réforme de l’imposition des entreprises III, Expertsuisse, Lausanne, September 2016
Actualités fiscales organisé par l’Ordre romand des experts fiscaux (OREF), l’Ordre genevois de la Chambre fiduciaire (OGCF) et Fiduciaire suisse, Genève, March 2016
Le step-up, International Fiscal Association, Berne, November 2015
Corporate tax reform III – The proposed measures from a cantonal perspective, Steuerkonferenz, Hochschule, Lucerne

Education

2006 – Certified tax expert exam
1999 – Bar exam
1994 – Law degree, University of Geneva (Switzerland)

Practice Areas

Tax

sectors

Private Clients

Insights

Global Reach