Sundack CPA supports businesses, professionals, and investors across New York City, Long Island, and throughout several other states.
We handle the accounting, tax, and financial systems that keep your operation running without surprises — no matter where you’re based or how many jurisdictions you operate in.

New York has some of the strictest compliance rules in the country, and most of our clients either operate here or have long-term connections to the state. We manage the numbers so your books stay accurate, your filings stay on track, and your decisions stay grounded in clean financial data.

 

At Sundack CPA, your success is our priority. We’re not just expert CPA's —we’re your financial partners, committed to helping you grow and thrive. 

Ready to see the Sundack CPA difference? Connect With Us Now!

Questions? Let's Connect

Where We Serve Clients

We work with clients across several regions, each with its own set of accounting and tax requirements. Our focus isn’t limited to a single market — we support companies, professionals, and investors wherever their operations or obligations exist.

New York City

We serve clients in all five boroughs. Most NYC businesses deal with strict tax rules, intensive reporting, and shifting regulations. Our team handles the accounting, tax planning, payroll, sales tax, and audit response work that NYC companies rely on.

Long Island

We support businesses throughout Nassau and Suffolk counties. Long Island companies depend on structured accounting, clean books, predictable cash flow, and ongoing tax planning. We manage the financial systems that keep these businesses steady year-round.

Clients Outside of New York

Many of our clients operate in other states or split work between multiple locations. We support businesses and investors in Florida, New Jersey, Connecticut, Delaware, Illinois, Pennsylvania, Texas, California, and other states tied to New York through residency, payroll, sales, or property ownership.

Multi-State Operations

Modern businesses rarely stay inside one state line. We assist companies with multi-state tax filings, sales tax compliance, nexus requirements, remote employees, out-of-state rentals, and cross-state payroll. As clients expand, we keep the entire financial picture organized across every jurisdiction.

 

At Sundack CPA, your success is our priority. We’re not just expert CPA's —we’re your financial partners, committed to helping you grow and thrive. 

Ready to see the Sundack CPA difference? Connect With Us Now!

Questions? Let's Connect

New York City

New York City demands accuracy. Businesses here deal with additional tax layers, complex regulations, and tighter oversight. We work with clients throughout Manhattan, Brooklyn, Queens, the Bronx, and Staten Island.

What We Do in NYC

  • Monthly accounting and bookkeeping

  • Corporate, partnership, and individual tax preparation

  • Year-round tax planning

  • Payroll management

  • Sales tax compliance

  • Audit support with NYC and NYS agencies

  • Guidance on UBT exposure and entity structure

Our NYC workflow is built to keep businesses compliant and prepared for scrutiny.

Who We Support in NYC

  • Restaurants

  • Medical and dental practices

  • Law firms

  • Real estate investors

  • Contractors and trades

  • Tech companies and MSPs

  • Retail and franchise operators

  • Consultants and solopreneurs

Long Island

Long Island companies rely on steady accounting and forward planning. We support organizations across Nassau and Suffolk, from small service companies to established firms managing multiple locations.

What We Do in Long Island

  • Month-end financials and reconciliations

  • Payroll processing

  • Sales tax filings

  • Year-round tax planning

  • Real estate accounting and investment support

  • Clean records ready for banks, partners, or potential audits

Who We Support in Long Island

  • Contractors and home service businesses

  • Medical practices

  • Family-owned companies

  • Real estate investors

  • Retail and local service providers

  • Professional service firms

  • Growing businesses preparing to scale

Clients Outside of New York

Not all our clients operate in New York — many work fully outside the state or manage business activity across several regions. These clients choose us because they want accounting that stays consistent no matter where their operations are located.

Where Our Out-of-State Clients Operate

We support businesses and investors in:

  • Florida

  • New Jersey

  • Connecticut

  • Delaware

  • Illinois

  • Pennsylvania

  • Texas

  • California

  • Georgia
    …and other states that share economic ties with New York.

Who We Support Outside NY

  • E-commerce sellers shipping nationwide

  • Remote-first companies with employees in multiple states

  • Real estate investors with multi-state rental portfolios

  • Professional service firms with clients across the U.S.

  • Individuals relocating from New York to low-tax states

  • Multi-entity owners managing income from several jurisdictions

We keep books aligned, taxes accurate, and filings consistent — without making you deal with multiple firms in different states.

Multi-State Accounting & Tax Support

Multi-state obligations create complexity quickly: different tax rules, different filing schedules, and different payroll requirements. We manage all of it under one organized system.

When Multi-State Issues Come Up

Typical triggers:

  • Hiring remote employees

  • Opening locations or working in more than one state

  • E-commerce sales across multiple states

  • Exceeding economic nexus thresholds

  • Owning rental property in different jurisdictions

  • Relocating from New York to another state

  • Managing multi-entity income streams

What We Handle for Multi-State Clients

  • Multi-state income tax filings

  • Sales tax registration and reporting

  • Nexus analysis and state registration

  • Payroll compliance for multi-state teams

  • Real estate and rental income reporting

  • Residency and domicile planning

  • Coordinated bookkeeping across all states

Get Started

Whether you’re based in NYC, Long Island, or operating in several states, you need accounting and tax support that stays consistent everywhere your business goes.

We help you stay organized, compliant, and prepared.

Why Businesses Choose Sundack CPA

We keep accounting, tax, and compliance straightforward — even when your business operates in multiple jurisdictions. Clients work with us because:

We prioritize accuracy and consistency

We understand New York’s complexity and how it affects businesses everywhere

We coordinate filings across states without gaps or conflicting advice

We build stable financial systems that scale with your business

We communicate clearly and directly — no vague reporting, no hidden issues

You get one CPA team managing all deadlines, filings, and accounting needs. No guesswork and no juggling multiple firms.

 

At Sundack CPA, your success is our priority. We’re not just expert CPA's —we’re your financial partners, committed to helping you grow and thrive. 

Ready to see the Sundack CPA difference? Connect With Us Now!

Questions? Let's Connect