Aviso de Privacidad

Integrity, responsibility and trust make OSY not only an excellent choice in the field of tax and legal consulting, but also the perfect option by providing comprehensive and technically sound solutions, thanks to our philosophy and extensive experience.


Our goal is to render high-level, specialized tax services to business entities and their stockholders, timely delivering tailor-made solutions, within a strictly legal framework, that address specific needs and fulfill the objectives proposed.


OSY is a boutique firm of business advisors that specializes in tax consulting and litigation, founded in 2001 as Ortiz, Sosa, Ysusi y Cía., S.C.


As of March 2016, Ortiz, Sosa Y Asociados, S.C. (OSY), is moving ahead in a new phase based on the experience, professionalism and personal attention which have always been our trademark.

We have three core values: technical specialization, personal service and top-quality work. As a result, we have developed the ability to handle a variety of made-to-measure services and solutions which provide value added to our clients.

OSY also bases its growth and expectations on the following:

Our Tax Services include:

The Legal Services

we offer include the following:

• Corporate restructurings

• M&A: mergers, spin off, acquisitions of companies

• Wealth management

• Financial services

• Preferential tax regimes (REFIPRES) and application of International Tax

• Procedures before the SAT

• Trusts (fibras, business, leasing, etc.)

• Tax advice on debt and share offerings on the Stock Market


• Processing of tax litigation

• Filing of amparo lawsuits against unconstitutional tax laws

• Handling final agreements with PRODECON

• Dealing with tax audits and correction of pending tax obligations

• Filing and follow-up on amicable procedures established in International Treaties


Analí Barba

Víctor Nava

Manuel Olivares

Eduardo Piña

Héctor Tirado

The quality of our services is based on a solid team of accountants and attorneys, all of whom are highly qualified and committed to their clients.


The ongoing technical, personal and professional development of the members of OSY is founded on the principles of ethical behavior, trust, responsibility, integrity and hard work.

Bosque de Alisos 58, 4° floor

Col. Bosques de las Lomas, C.P. 05120

Mexico City

+52 55 1084 7000