First-Year Startup Tax Guide: What New Business Owners Need to Know

Your first year in business, you're making tax decisions before you know they're tax decisions — the entity you form, the account you deposit into, the receipts you do or don't keep. A handful of cheap, early choices prevent nearly all of the expensive April surprises. Here's the first-year playbook for founders, with the 2026 rules built in.

Which entity should you actually start with?

The honest answer for most first-year businesses: simpler than you think.

• Sole proprietorship — the default if you just start selling. Zero setup, income lands on Schedule C of your personal return. Fine for testing an idea; no liability shield.
• LLC — the standard first move. Liability protection with almost no tax consequences, because a single-member LLC is taxed exactly like a sole proprietorship (a multi-member LLC like a partnership) unless you elect otherwise. Formation costs vary by state.
• S corporation — not an entity you form, but a tax election (usually layered on an LLC) that can reduce self-employment tax once profits are consistently strong — commonly worth modeling somewhere north of $60,000-$80,000 of net profit, against added payroll and filing costs. The election window is tight (generally within about 75 days of forming, or by mid-March for a calendar-year business), though late-election relief often exists. Run your own numbers in two minutes with our S-corp calculator.
• C corporation — the right call mainly when venture capital, outside shareholders, or specific stock benefits (like QSBS) are in the plan. It files its own return at a flat 21% and adds a second layer of tax on dividends, which is why "LLC now, convert if needed" is the usual founder path.

The most common first-year entity mistake isn't picking wrong — it's paying for structure you don't need yet. Entity choice is revisitable; start where your risk and revenue actually are.

What should you set up in the first 30 days?

Five foundations, all boring, all compounding:

1. EIN — free at IRS.gov in minutes. You'll need it for banking, payroll, and most registrations even as a sole proprietor.
2. A dedicated business bank account — the single highest-leverage move on this list. Clean separation is what makes bookkeeping cheap, deductions defensible, and your liability shield real (courts pierce LLCs with commingled funds).
3. Bookkeeping from day one — software, a spreadsheet, or a bookkeeper; anything but "I'll reconstruct it later." Categorize monthly while you still remember what things were.
4. State and local registrations — state tax accounts, local business licenses, and sales tax permits where you have obligations. If you sell products (especially online), note that most states require collection once you cross economic-nexus thresholds, commonly around $100,000 of in-state sales — a problem worth understanding before it's retroactive.
5. A receipts habit — photograph everything into one place. Startup-phase receipts matter extra, for the deduction rules below.

How do startup costs get deducted?

Costs you incur before opening day follow a special rule (Section 195). In your first year you can deduct up to $5,000 of startup costs (market research, pre-opening ads, travel, consultants) plus up to $5,000 of organizational costs (state formation fees, legal drafting) — each reduced dollar-for-dollar to the extent that category exceeds $50,000. Whatever isn't deducted immediately amortizes over 180 months.

A hedged 2026 example: you spend $8,000 getting a business ready and open in July 2026. You'd typically deduct $5,000 immediately, and the remaining $3,000 amortizes at about $17/month — roughly $100 more in year one, with the rest spread over 15 years. The catch that surprises founders: these deductions require the business to actually launch, and equipment isn't a startup cost — it's an asset, handled separately (and generously) below.

When do you have to start paying taxes?

There's no grace period for year one — profit is taxable from the first dollar, and nobody withholds for you:

• Self-employment tax (15.3% on net earnings, for sole props/LLC members) plus income tax at your bracket both apply to profit, whether or not you paid yourself a cent. You're taxed on what the business earns, not what you withdraw.
• Quarterly estimated payments are expected once you'll owe $1,000+ for the year — for 2026: April 15, June 15, September 15, and January 15, 2027. First-year founders have a built-in safe harbor: pay 100% of last year's total tax (110% if prior-year AGI topped $150,000) and you're penalty-proof even if the business takes off. The full mechanics are in our quarterly due-dates guide.
• A rule of thumb, not a plan: set aside 25-30% of profit in a separate tax savings account, transfer it every time you pay yourself, and true it up with a professional mid-year.

Which first-year deductions and elections matter most?

The 2025 tax law left new businesses an unusually favorable menu for 2026 — the highlights, all subject to your facts:

• Equipment: Section 179 expensing up to $2,560,000 (2026) and permanent 100% bonus depreciation mean most equipment, computers, and furniture can be written off in year one. Small purchases can simply be expensed under the $2,500 de minimis safe harbor.
• QBI deduction: pass-through owners generally deduct 20% of qualified business income — now permanent, with 2026 phase-out ranges starting around $201,775 single / $403,500 joint, and a new small floor (at least $400) for anyone with $1,000+ of active business income.
• R&D costs: domestic research and experimentation expenses are immediately deductible again (restored for 2025 onward) — a big deal for software and product startups that were briefly forced to amortize.
• Home office, mileage (72.5 cents/mile for 2026), health insurance premiums for the self-employed, and retirement plans (SEP or solo 401(k), up to $72,000 combined for 2026) round out the standard stack.
• Elections to get right the first year: cash vs. accrual accounting method and your depreciation choices are set on the first return and are annoying to change later. This is the one return where professional preparation most reliably pays for itself. The broader landscape is in our 2026 tax changes hub.

What if your first year is a loss — and how do you protect it?

Losses are normal in year one, and they're valuable if handled correctly:

• A genuine business loss on Schedule C generally offsets your other income (a W-2 salary, a spouse's income) in the same year, subject to at-risk, excess-loss, and related limits; unused net operating losses carry forward against future profits (generally limited to 80% of taxable income in the year used).
• The hobby-loss rules are the guardrail: deduct losses year after year without behaving like a business and the IRS can reclassify the activity, disallowing losses entirely. Profit in three of five years creates a safety presumption, but the real defense is conduct — separate accounts, records, a plan, and adjustments when something isn't working.
• Document the loss year as carefully as a profit year. Carryforwards, basis, and startup amortization all depend on year-one numbers being right.

Most founders come to us in month eleven with a shoebox and a deadline; the ones who come in month two spend less and keep more — but it's never too late. Problems come here to get solved. Bring the whole tangle to a free 15-minute call and we'll tell you what actually needs attention this year versus what can wait.

FAQ

Do I need to file a tax return if my new business made almost nothing?

If self-employment net earnings hit just $400, a return with Schedule SE is required. And even below thresholds, filing a loss year is usually smart — it documents startup deductions and starts carryforwards you'll want against next year's profit.

Can I deduct expenses from before I formed the LLC?

Generally yes — legitimate pre-launch costs become startup/organizational costs under the $5,000 + $5,000 rules once the business opens, even if you paid them personally before the entity existed. Keep the receipts and record them properly in the first year; they're easy money to lose.

Should I pay myself a salary in year one?

Sole proprietors and single-member LLC owners can't be on their own W-2 payroll — you take draws, and taxes are calculated on profit. Salaries become mandatory only once you're an S corporation (reasonable compensation) or C corporation. Until then, "paying yourself" is a cash-flow decision, not a tax event.

What records does the IRS actually expect a first-year business to keep?

Enough to reconstruct income and every deduction: bank statements, invoices, receipts, mileage logs, asset purchase documents, and formation papers — kept at least three years after filing (longer for assets and payroll). A $20/month bookkeeping habit satisfies this almost automatically.

When should a startup switch from DIY taxes to a professional?

The trigger points: your first profitable year, hiring anyone, multi-state sales, an S-corp election, or outside investors — whichever comes first. Year-one returns set elections and baselines that compound for years, which is why even DIY-forever founders often buy one professional year up front.

Reviewed by the WAYG tax team · Updated July 2026