Business Accountant Long Island | Tax Accountant Nassau & Suffolk | OnPoint
Business Accountant for Long Island
Expert tax preparation, bookkeeping, and accounting for Long Island small businesses, LLCs, S-Corps, and sole proprietors. Flat-fee pricing. No surprises.
Long Island's Business Tax & Accounting Experts
OnPoint Business Tax & Accounting serves Long Island business owners across Nassau and Suffolk Counties — from Garden City and Great Neck to Huntington, Babylon, and Smithtown. Whether you run a contracting business, a medical practice, a retail shop, or a professional services firm, our enrolled agents and tax professionals handle your books and taxes so you can focus on growing your business.
We specialize in small and mid-size businesses that need more than a seasonal tax preparer. From monthly bookkeeping and QuickBooks setup to S-Corp elections and multi-year unfiled returns, we deliver complete, year-round financial support at a flat fee you'll know upfront.
What's Included
A complete Long Island accounting and tax service — not just a transaction.
Business Tax Preparation
Federal and NY State returns for LLCs, S-Corps, C-Corps, partnerships, and sole proprietors — filed accurately and on time.
Bookkeeping & QuickBooks
Monthly bookkeeping, bank reconciliations, and QuickBooks setup and cleanup so your financials are always current.
Tax Planning
Year-round strategy to reduce your tax liability — S-Corp elections, retirement contributions, depreciation, and more.
NYS Compliance
NYS sales tax filings, payroll tax compliance, and all state and local obligations handled by professionals who know New York.
Unfiled & Back Taxes
Behind on multiple years? We prepare and file all outstanding returns and help you resolve IRS and NYS balances.
New Business Formation
LLC and corporation formation, EIN registration, and first-year tax setup for new Long Island businesses.
Flat-Fee Pricing — No Surprises
You know exactly what you'll pay before we start. No hourly billing, no hidden charges.
100% In-House — Never Outsourced
Every return, every filing, every call is handled by our own licensed team.
Long Island Business Owner — How Much Are You Overpaying in Taxes?
Select your entity type and answer 3 quick questions — get your personalized savings estimate in seconds. Free, no signup required.
No signup · No obligation · 3 questions
Everything We Handle for You
OnPoint delivers a complete, end-to-end Long Island accounting and tax service — no hand-offs, no surprises.
- Business tax returns — LLC, S-Corp, C-Corp, partnership
- Monthly bookkeeping and bank reconciliations
- QuickBooks setup, cleanup, and training
- NYS sales tax filings
- Payroll tax compliance and filings
- Unfiled and back-year tax returns
- IRS and NYS tax resolution
- New business formation and EIN setup
- Tax planning and S-Corp elections
Why OnPoint?
Long Island's Trusted Business Tax Experts
- Circle of Excellence 2025 Award Recipient
- 5-star rated on Google Reviews
- Serving NYC & NJ businesses for over a decade
- Flat-fee pricing — you know the cost upfront, always
- 100% in-house — your work is never outsourced or offshored
- Bilingual staff — English & Spanish
- In-person, virtual, and drop-off options
Client Stories
What NYC & NJ Business Owners Say
"OnPoint is hands-down the best business tax accountant in Brooklyn. They found deductions I never knew existed, saved my LLC thousands in taxes, and made the whole process completely stress-free. I won't go anywhere else."
Maria T.
Owner, Bella Mia Boutique — Brooklyn, NY
"I've worked with several Manhattan accountants over the years, but OnPoint is on another level. Their real estate tax expertise and S-Corp knowledge saved my business over $14,000 last year. Highly recommend for any NYC business owner."
James R.
CEO, R&R Property Group — Manhattan, NY
"As a new LLC owner in Queens I was overwhelmed by business taxes. OnPoint walked me through everything — bookkeeping setup, quarterly estimates, and my first business tax return. Now I feel totally in control of my finances."
Sofia M.
Founder, SM Consulting LLC — Queens, NY
"OnPoint handles our payroll, bookkeeping, sales tax filings, and annual business tax return. Everything is accurate and on time. Having a reliable Bronx tax accountant on our side lets me focus on running my restaurant."
Kevin L.
Owner, Golden Dragon Restaurant — Bronx, NY
"OnPoint is the best small business accountant on Long Island. They cleaned up two years of messy books, caught deductions my previous accountant missed, and got me a refund I didn't even know I was owed. Exceptional service."
Denise W.
Owner, Denise's Hair Studio — Long Island, NY
"OnPoint handles all my New Jersey contractor tax filings, quarterly estimates, and business tax preparation. They're always reachable, always accurate, and have already saved me from two IRS notices. Best business accountant in NJ."
Carlos V.
Principal, Vega Construction — Newark, NJ
"I needed a New Jersey accountant who truly understood small business taxes and S-Corp elections. OnPoint nailed both. The S-Corp election they recommended saved me over $8,000 in self-employment tax last year alone."
Rachel B.
Founder, Bright Start Tutoring — Montclair, NJ
"I used to dread tax season. Now I look forward to my year-end review with OnPoint because I know they'll find ways to reduce my business taxes. The best tax accountant in Brooklyn for contractors and tradespeople."
Anthony P.
Owner, Park Slope Plumbing — Brooklyn, NY
"Our payroll taxes and NYC business tax situation were a mess when we came to OnPoint. Within 90 days they had everything organized, compliant, and running smoothly. The most knowledgeable Manhattan tax accountant we've ever worked with."
Linda C.
CEO, Citywide Staffing Solutions — Manhattan, NY
"OnPoint helped me form my LLC, set up QuickBooks, and filed my first business tax return in the Bronx. They made starting a business feel manageable. I refer every small business owner I know to them."
Marcus J.
Owner, MJ Auto Detailing — Bronx, NY
"As a restaurant owner in Queens, sales tax compliance and payroll taxes were always stressful. OnPoint handles all of it — filings, audits, quarterly returns. I haven't received a late notice since switching to them."
Priya S.
Founder, Priya's Kitchen — Queens, NY
"OnPoint understands real estate taxation better than any accounting firm I've used. They handle our partnership returns, depreciation schedules, 1031 exchange planning, and Long Island property tax strategy. Worth every dollar."
Tom H.
Partner, Harbor View Realty — Long Island, NY
Work with a Long Island Business Accountant
We serve Long Island businesses remotely and in-person at our Manhattan office. Call us or request a free quote today.
NYC Office — 100 Church Street, New York, NY 10007
Serving Long Island businesses remotely and in-person. Mon–Fri 9 AM–6 PM & Sunday 10 AM–4 PM.
Our Tax & Accounting Services
Common Questions
Long Island Business Accountant — FAQs
Common questions from Long Island business owners before working with us.
Still have questions? We're happy to talk through your specific situation — no obligation.