William Sebastiano

Our Partners

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— Practice Group: 
— Practice Group: 
State & Local Tax Services

Bill oversees Porte Brown’s Governmental Compliance Practice Group, which represents companies and individuals before the Internal Revenue Service, Illinois Department of Revenue, Department of Employment Securities and other state revenue departments. His compliance team helps ensure that companies and individuals have supporting documentation necessary to produce the best results. As an additional benefit to clients, Bill is an Enrolled Agent, eligible to practice before the Internal Revenue Service.

The compliance team keeps the staff up-to-date with current tax rules. Working at client sites enables the staff to anticipate and resolve issues. This knowledge ensures Bill’s team will provide data and other information clients need – when they need it.

"I love what I do," states Bill. Whether Bill is providing excellent client counsel, mentoring staff or presenting educational seminars to local organizations or financial institutions, he strives to lead by example.

Professional Experience

Bill began his Porte Brown career as a staff accountant at the firm in 1984.  The firm's progressive culture and entrepreneurial approach allowed Bill to build upon his strengths, develop additional industry experience and advance to partner in 1997.


B.S., Accounting, DePaul University, Chicago, Illinois


Enrolled Agent

Civic Involvement

Algonquin Rotary Club: Treasurer, Board Member; recipient of "Service Above Self Award (2008)

Algonquin Police Commission: Board Member

Eagle Scout: Committee Chair, Scoutmaster

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Did You Know?

At Porte Brown we know that interesting people make for interesting stories. We pride ourselves on being relatable professionals with family, friends, interesting hobbies, and a deep appreciation for individual growth!

Did you know Bill...

• Is one of the youngest eagle scouts at age 15 ½!

• Enjoys working in the yard and garden!

• Still owns the 1st car purchased in 1968!

• Loves to shoot handguns and shotguns!

• Is a gear head and can work on his own car!

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