Messy books don’t just cause stress at filing time—they quietly erase deductions you’ve already earned. In New York, where state and city taxes add layers of complexity, the cost of missed write-offs can snowball fast. Use this checklist to tighten your records now and capture deductions you might be leaving on the table. (General guidance only—always confirm specifics with your tax pro.)
- Home office (exclusive & regular use)
If you run the business from a dedicated area of your apartment or home, you may qualify for the home-office deduction. Two common misses: (a) the space must be exclusively for business, and (b) you can choose the simplified method or actual-expense method (allocating rent/mortgage interest, utilities, renters insurance). Clean books help you track utilities and rent portions accurately—critical when NYC rents are high.
- Vehicle expenses (mileage vs. actual)
Owners often forget to log mileage or mix personal and business costs. Choose the standard mileage rate or actual expenses (gas, insurance, maintenance, depreciation) and stick to it. Don’t lose track of tolls and parking for client visits in the boroughs; those are frequently missed even when mileage is captured.
- Business meals (50% allowed)
Meals with a clear business purpose and a documented attendee list are 50% deductible. Lack of detail—who, where, why—kills this deduction at audit time. Keep itemized receipts and link each to a client or project in your ledger. Entertainment still isn’t deductible, so separate it from meals.
- Merchant processing & bank fees
Credit-card processing fees, platform payout fees, and monthly bank service charges are fully deductible but easy to miss if you don’t reconcile every statement. For New York retailers with heavy card volume, this line alone can be thousands of dollars across a year.
- Software & SaaS subscriptions
From bookkeeping and project management to design and CRM tools, recurring subscriptions are valid write-offs. Owners often forget annual renewals or fail to categorize app store purchases correctly. Keep a master list of active tools and reconcile against statements monthly.
- Professional fees (legal, tax, advisory)
Attorney consultations, tax prep, and advisory retainers are deductible. Many owners pay sporadically from personal cards, then forget to reimburse the business. Track all invoices, even those paid outside the business account, and record the expense when incurred. If you use a professional bookkeeping service, make sure those invoices are captured, too.
- Advertising & marketing
Website design and maintenance, SEO, pay-per-click ads, directory listings, boosted social posts, and printed materials all qualify. The most common error is capitalizing routine marketing when it should be expensed. Keep invoices tied to campaign dates and tag spend by channel to support the deduction and measure ROI.
- Phone & internet (business portion)
If you use a single mobile line and home internet for both personal and business, document a reasonable business-use percentage and apply it consistently. Inconsistent allocations (or none at all) are a classic way to under-deduct. Save monthly statements and note any business-only lines or hotspots used for travel.
- Depreciation & Section 179 (equipment and furniture)
Large purchases—computers, monitors, POS systems, machinery, office furniture—are often capitalized but never depreciated, or they’re expensed incorrectly. Section 179 and bonus depreciation can accelerate deductions, but only if assets are recorded with purchase date, cost, and in-service date. Keep vendor invoices, tag assets by category, and review an annual fixed-asset rollforward so you don’t miss first-year elections or write-offs when assets are disposed.
- Repairs & maintenance vs. improvements
Leaky faucet? Minor roof patch? Swapping a hard drive? True repairs are deductible now, while improvements are typically capitalized and depreciated over time. Owners often default to capitalizing everything (and miss current deductions) or expensing everything (and risk audit adjustments). Keep descriptions detailed on bills, separate parts from labor when possible, and talk with your tax pro about safe-harbor thresholds (e.g., the de minimis safe harbor) that may let you expense smaller-ticket items consistently.
- Insurance premiums (GL, professional liability, cyber, workers’ comp)
Premiums for general liability, professional liability, cyber, and inland marine/tool coverage are deductible, but they’re commonly buried in lump-sum bank withdrawals or booked as “miscellaneous.” In New York, don’t forget state-mandated DBL/PFL (short-term disability and paid family leave) and workers’ comp—especially for contractors and service businesses with field staff. Track each policy by line of coverage, record installments or audits to the correct period, and attach the declarations page to your expense record.
- Health insurance and retirement contributions
Self-employed health insurance (subject to rules and income limits) and employer retirement contributions (SEP-IRA, SIMPLE-IRA, or 401(k) match/profit share) are among the most valuable deductions—yet frequently underfunded or missed because cash forecasts are fuzzy. Clean monthly books let you project year-end profit early, choose the right plan, and time contributions before deadlines. Keep payroll reports, plan docs, and contribution confirmations filed with your year-end package so your tax preparer captures every dollar.
How to lock these in before NY tax season
- Reconcile monthly, then review quarterly. Bank/credit card reconciliations come first; deduction review comes second. Create a quarter-end checklist that includes scanning for subscriptions, fees, insurance audits, and asset purchases.
- Attach receipts and notes. For meals, write the who/why on the receipt. For equipment, attach the invoice and warranty. For repairs, note what was fixed vs. improved.
- Tag by purpose. Use consistent categories (e.g., “Merchant Fees,” “Software,” “Repairs & Maintenance,” “Insurance – GL,” “Insurance – Cyber”). Consistency beats perfection when you’re looking back at 12 months of data.
- Separate business and personal. If you must use a personal card in a pinch, reimburse the business promptly and document it so deductions don’t get stranded in a personal statement.
- Schedule a pre-season review. In late fall, run a draft Profit & Loss and balance sheet. Confirm assets to be placed in service, catch any missing subscriptions/fees, and plan retirement contributions before December 31 (or the plan’s setup deadline).
New York’s layering of state and city taxes—and nuances like mandated insurances—make clean, timely records more than an administrative chore; they’re a direct path to lower taxable income and fewer April surprises. Tighten your process now, and these 12 write-offs can move from “easy to miss” to “automatically captured,” year after year.
