Trusted CPA & Accounting Services

Helping Individuals And Businesses Achieve Financial Success With Trusted CPA Services

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Welcome to William Diker, CPA

William Diker, CPA is a trusted accounting firm providing professional tax, accounting, bookkeeping, payroll, and financial consulting services for individuals and businesses. Backed by more than 45 years of experience, we are committed to delivering accurate financial guidance, responsive communication, and personalized service. Based in New York, we proudly serve clients throughout the United States and internationally. Our mission is to help clients achieve long-term financial success through honest advice, dependable expertise, and tailored accounting solutions.

Certified Professional Expertise

As a Certified Public Accountant with more than 45 years of experience, we provide knowledgeable accounting, tax, and financial guidance for individuals and businesses. We stay current with changing tax laws and financial regulations to deliver accurate, dependable solutions you can trust.

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Responsive Client Communication

We believe clear, timely communication is essential to building lasting client relationships. Our team is committed to being responsive, answering your questions promptly, and keeping you informed every step of the way.

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Over 45 Years of Experience

For more than four decades, we have helped clients navigate tax preparation, accounting, bookkeeping, payroll, and financial planning with confidence. Our extensive experience allows us to provide practical solutions tailored to each client's unique financial goals.

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Integrity-Driven Service

We believe honesty, transparency, and putting our clients first are the foundation of everything we do. We take pride in building long-term relationships by providing ethical guidance, personalized service, and financial advice that is always in your best interest.

Financial Clarity Trusted Across New York Communities

Numbers tell a story, and getting that story right can shape everything from your next hire to your eventual retirement. For more than 45 years, William Diker, CPA has helped individuals and businesses across New York and beyond turn complex finances into clear, confident decisions. We combine deep tax knowledge with responsive, personal attention, so you always know exactly where you stand. Whether you need a return filed, books balanced, payroll managed, or a business structured properly, our team delivers accuracy you can trust. We also provide international accounting and tax services, helping clients with cross-border financial matters with the same level of precision and personalized support.

Our Services

Tax Preparation Services

We prepare accurate, compliant tax returns for individuals and businesses, uncovering every deduction and credit you qualify for. Our process reduces errors, limits audit risk, and keeps you filing confidently.

Small Business Accounting

Running a business is demanding enough without financial guesswork. We manage your accounts, reconcile records, and produce clear statements so you understand your numbers and make smarter decisions year round.

Corporate Tax Services

Corporate returns carry complexity and consequences. We handle federal and state filings, entity level planning, and compliance for corporations of every size, protecting your bottom line while keeping you compliant.

Tax Planning Services

Smart planning beats scrambling at deadline. We look ahead across the full year, structuring income, deductions, and timing to lower your liability legally and position you for stronger financial results.

Bookkeeping Services

Clean books are the foundation of every sound decision. We record transactions, reconcile accounts, and maintain ledgers so your financial picture stays accurate, current, and ready when you need it.

Payroll Services

Payroll mistakes cost time, money, and trust. We calculate wages, withhold taxes correctly, and process payments on schedule, keeping employees paid accurately and your business compliant with every reporting requirement.

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Dependable Accounting Built Around Your Long Term Success

Great advice is not measured by tax season alone, but by the confidence you carry all year long. For more than 45 years, clients across New York and around the country have trusted William Diker, CPA for honest guidance, dependable expertise, and solutions built around real goals. We answer when you call, explain what your numbers actually mean, and treat your success as our own. Whatever your financial questions, we bring accuracy, integrity, and personal attention to every one. Reach out today and let decades of proven experience start working for you.

FREE 30-Minute CPA Consultation

Whether you need help with personal taxes, small business accounting, tax planning, payroll, bookkeeping, or IRS issues, we're here to help.


Meet one-on-one with a Certified Public Accountant to discuss your financial needs, ask questions, and receive professional guidance—at no cost and with no obligation.

Schedule your FREE 30-minute consultation today by completing the form below.

  • Personal & Business Tax Services
  • Small Business Accounting
  • Tax Planning Strategies
  • Payroll & Bookkeeping
  • IRS Representation & Resolution

Frequently Asked Questions

  • What accounting and tax services do you provide?

    We offer a full range of accounting and tax services for both individuals and businesses, including tax preparation, tax planning, bookkeeping, payroll, financial reporting, QuickBooks support, and business consulting. Our goal is to provide personalized financial solutions that help you stay compliant while maximizing your financial success.

  • Do you work with clients outside of New York?

    Yes. While we are based in New York, we proudly serve clients throughout the United States and internationally. We use secure digital tools to provide convenient communication, document sharing, and virtual consultations regardless of your location.

  • How can a CPA help my business?

    A CPA does much more than prepare tax returns. We help businesses improve financial organization, reduce tax liabilities, maintain accurate records, manage payroll, and develop strategies for long-term growth. Our proactive approach allows business owners to focus on running their company with confidence.

  • How do I get started with William Diker, CPA?

    Getting started is simple. Contact us by phone or complete our online form to schedule a consultation. We'll discuss your accounting or tax needs, answer your questions, and recommend the services that best fit your personal or business financial goals.

The QUEENS VILLAGE Small Business Excellence Awards rewards outstanding small businesses that serve their local area.


Each year, our selection committee selects companies that we believe have achieved outstanding marketing success in their business category. These are small businesses that enhance the positive image of small businesses through service to their customers and community.


This notification email is announcing that the QUEENS VILLAGE Small Business Excellence selection group has chosen William Diker, CPA for the 2017 QUEENS VILLAGE Small Business Excellence Award in the Accountants category.