Meet The Firm

Mach and Associates CPA P.A. is a full-service Certified Public Accounting firm licensed in the state of New Jersey. All our CPA's hold valid NJ State CPA Certificates.

Meet The Firm:

Jon Mach, CPA

Jon graduated in 1989 from the Wharton School of the University of Pennsylvania and has worked in public accounting since then. He obtained his CPA license in 1991, joined the firm in 1997, and was made partner in 2000. Jon specializes in providing individuals and small businesses income tax preparation and compliance, preparing financial statements, and developing tax strategies to help his clients achieve their goals.

Jon is also the Managing Partner of Mach & Associates CPA P.A. As the MP, Jon oversees the delivery of the firm’s high-quality client service, and leads the office and its people.

Jon lives in Fair Lawn, NJ. Jon has three kids, Ilan, Arielle, and Yarden. When not servicing his clients, you can likely find Jon at Yankees Stadium or at a classic rock concert!

Jon can be reached via email at, at his office phone (201) 797-8338 x309, or on his cell phone (201) 681-3268.

Harry Zarrow, CPA

Harry has been a CPA since 1982, after attending Washington University and graduating from Fairleigh Dickson University. Harry joined the firm after college and made partner in 1985. Harry has been providing his clients more than 40 years of tax, accounting, compilation, review, and auditing services.

Harry lives in Fair Lawn, NJ with his wife, Norma, and tiny dog, Tino. He has two grown kids, Alex, a nurse, and Aaron, a professional musician. When not preparing financial statements and finalizing tax returns, Harry enjoys spending time with his family at his vacation home in Florida!

Harry can be reached via email at or at his office phone (201) 797-8338 x303.

Len Kaplan, CPA

Len has been a practicing CPA for nearly 50 years, starting his career after serving in the U.S. Army from 1966 to 1969. He graduated from Fairleigh Dickinson University earning a Bachelor of Science degree in accounting. Len joined the firm in 1976, and was admitted into the partnership in 1982.

Len provides a wide variety of services to his clients. He has extensive knowledge in numerous areas including business and personal tax, accounting and QuickBooks consulting. He values the relationships he has built with his client over the many years.

He is a member of the American Institute of Certified Public Accountants and the New Jersey Society of Certified Public Accountants.

Len is now semi-retired and enjoys playing golf and billiards. He is married to his wife, Beverlee, has two grown children, and two grand kids.

Len can be reached via email at or at his office phone (201) 797-8338 x302.

Rob Premselaar, CPA

Rob joined ZMKK in January 2018. Prior to working at ZMKK, Rob was an audit manager at KPMG, and then a Director of Internal Audit at Merck. Rob has held his NJ CPA license since 2012, which he obtained while working for KPMG. Rob graduated undergrad from Rutgers Business School with a finance and economics degree, and obtained his MBA from Rutgers Newark. Rob provides his clients with tax preparation and compliance services, QuickBooks consulting, and performs financial statement compilations, reviews, and audits.

In addition, Rob provides expert tutoring and counseling in the field of accounting and finance. His tutoring experience includes instruction to all levels of accounting (high school, college, MBA), CPA preparation, and accounting/finance professionals. Over the last 5 years, Rob has tutored nearly 100 students across the country, helping them succeed in the CPA exam, pass that tough accounting final, or counseling them through their accounting or audit careers.

Rob lives in Englewood, NJ with his wife, Anna, and son, Daniel. When not at the office, you can likely find Rob at a Yankees game or at his vacation home on the Jersey Shore!

Rob can be reached via email at or at his office phone (201) 797-8338 x304.

Amy Osborne

Amy joined ZMKK 2010 and is the office manager, with over 25 of years’ experience. Amy’s emphasis has been as a generalist helping small business and individual clients with accounting, tax, and QuickBooks issues. In addition to her accounting and bookkeeping services she provides clients, Amy is the office manager with the responsibility of managing the daily operations of the ZMKK office.

Amy can be reached via email at or at her office phone (201) 797-8338 x312.

Linda Haydinger

Linda joined the firm in 2010 as the firm’s administrative assistant, with over 40 years’ experience. Linda personally knows and has worked with many of our clients, both as individuals or businesses, throughout her career. Linda assists in running the daily operations of the firm.

Linda can be reached via email at or at her office phone (201) 797-8338 x305.

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