Tax Planning for Startups (Don't Screw This Up)

Tax mistakes are expensive and sometimes catastrophic. Here's what founders need to know about startup taxes.
Taxes aren’t exciting, but tax mistakes can be painful and expensive. A little knowledge helps you avoid common pitfalls and work effectively with your accountant.
This isn’t tax advice (get an accountant), but it’s the context you need.
C-Corp Tax Basics
If you’re a Delaware C-Corp (most VC-backed startups):
Corporate Tax
C-Corps pay tax on profits at the corporate level.
Federal rate: 21% State rate: Varies (0-13%+ depending on state)
Good news for startups: If you’re not profitable, you don’t pay corporate income tax. Most startups don’t pay federal income tax for years because they’re not profitable.
Pass-Through vs. Corporate
C-Corps have “double taxation”:
1.
Corporation pays tax on profits
2.
Shareholders pay tax on dividends
But startups rarely pay dividends. You’re reinvesting everything. Double taxation matters more for profitable companies distributing cash.
Net Operating Losses (NOLs)
Losses can offset future profits. If you lose $1M this year and profit $500K next year, you can use losses to reduce taxable income.
Rules have changed:
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Post-2017 NOLs can only offset 80% of taxable income
•
But they can carry forward indefinitely
NOLs are valuable. Track them.
Founder Tax Situations
83(b) Elections
When founders receive stock subject to vesting, they can file an 83(b) election to be taxed on the stock’s value at grant (usually very low) rather than at vest (potentially much higher).
Example without 83(b):
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Receive stock worth $0.001/share at grant
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Two years later, vest when worth $10/share
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Pay ordinary income tax on $10/share
Example with 83(b):
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Receive stock worth $0.001/share at grant
•
File 83(b), pay tax on $0.001/share (negligible)
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At vest, no additional tax
Critical: Must file within 30 days of receiving stock. No exceptions, no extensions. Miss it and you can’t fix it.
Your lawyer or incorporation service should remind you, but don’t rely on them. Calendar it yourself.
QSBS (Qualified Small Business Stock)
QSBS exclusion can eliminate federal capital gains tax on qualifying stock sales.
Requirements:
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C-Corp stock
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Company has < $50M in assets at issuance
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Stock held for 5+ years
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Various other conditions
Benefit: Up to $10M (or 10x basis) of gains excluded from federal tax.
This is significant. If you’re a founder who eventually sells stock, QSBS can save millions in taxes.
Track your QSBS eligibility. Don’t accidentally disqualify yourself.
Stock Option Taxes
If you receive options:
ISOs (Incentive Stock Options):
•
No tax at grant or exercise (usually)
•
AMT (Alternative Minimum Tax) may apply at exercise
•
Long-term capital gains if you hold 2 years from grant, 1 year from exercise
NSOs (Non-Qualified Stock Options):
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No tax at grant
•
Ordinary income at exercise (spread between exercise price and FMV)
•
Capital gains/losses on subsequent sale
ISOs are more tax-efficient but have more rules. Your accountant should advise based on your situation.
Company Tax Obligations
Payroll Taxes
When you have employees, you must:
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Withhold federal income tax, Social Security, Medicare
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Pay employer portion of Social Security and Medicare
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File quarterly (Form 941) and annually (W-2s, W-3)
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Handle state withholding
Use payroll software (Gusto, Rippling). Don’t DIY this.
Contractor Reporting
If you pay contractors $600+ in a year:
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Get W-9 before paying
•
Issue 1099-NEC by January 31
•
Don’t misclassify employees as contractors
Delaware Franchise Tax
Delaware corporations pay annual franchise tax. Two methods; you usually want the “assumed par value” method for startups (results in lower tax).
Minimum: ~$225/year Due: March 1
Your registered agent should remind you.
State Taxes Where You Operate
If you operate in states other than Delaware (you almost certainly do):
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Foreign qualification (registering to do business)
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State income tax
•
Possibly other state taxes
Your accountant should advise on nexus and obligations.
Sales Tax
If you sell to customers in the US, you may owe sales tax:
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Rules vary by state
•
“Nexus” determines where you must collect
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SaaS taxability varies by state (some states tax it, some don’t)
This is complex. Use Stripe Tax, TaxJar, or Avalara to automate, and get accountant advice.
Tax Calendar
January:
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W-2s and 1099s due (January 31)
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Quarterly estimated tax (January 15 for Q4)
March:
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Delaware franchise tax (March 1)
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S-Corp/partnership tax returns (March 15)
April:
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C-Corp federal tax return (April 15)
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Quarterly estimated tax (April 15 for Q1)
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Personal tax returns (April 15)
June:
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Quarterly estimated tax (June 15 for Q2)
September:
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Extended C-Corp returns (October 15 if extended)
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Quarterly estimated tax (September 15 for Q3)
Your accountant handles most of this, but know the deadlines.
Working with Your Accountant
What to Provide
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Access to accounting software
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Bank and card statements
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Revenue data (Stripe, invoices)
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Cap table and equity transactions
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Major contracts
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Answers to their questions
Questions to Ask
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Are we in compliance with all jurisdictions?
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What elections or filings should we consider?
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How do we minimize tax legally?
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What records should we keep?
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What changes should we anticipate?
Proactive vs. Reactive
Good accountants do tax planning throughout the year, not just at tax time:
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Structure decisions tax-efficiently
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Time income and expenses
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Plan for future events
If your accountant only talks to you at tax time, find a better one.
Common Tax Mistakes
Missing 83(b) deadline: Catastrophic for founders. File within 30 days.
Misclassifying employees as contractors: IRS penalties plus back taxes.
Ignoring state obligations: Operating without foreign qualification or missing state taxes.
Poor record keeping: Can’t support deductions without documentation.
Late payroll tax deposits: Penalties and interest add up fast.
Not planning for QSBS: Accidentally disqualifying stock from the exclusion.
DIY when you shouldn’t: Complex situations need professional help.
Tax-Efficient Practices
Timing
If you can choose when to recognize income or expenses, consider timing:
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Accelerate expenses into the current year if profitable
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Defer income if possible
•
Understand year-end strategies with your accountant
R&D Tax Credits
Startups may qualify for R&D tax credits for product development activities.
For startups with no tax liability, credits can offset payroll taxes (up to $500K/year for qualified small businesses).
Ask your accountant about R&D credits.
Documentation
Keep records:
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Receipts for expenses
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Business purpose for travel and meals
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Contracts and invoices
•
Equity documents
If audited, documentation is your defense.
Key Takeaways
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Most startups don’t pay corporate income tax because they’re not profitable
•
83(b) elections must be filed within 30 days—no exceptions
•
QSBS can eliminate capital gains tax on qualifying stock—track eligibility
•
Use payroll software for payroll taxes—never DIY
•
Know your sales tax obligations and automate collection
•
Work with a startup-experienced accountant who does planning, not just filing
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Keep documentation for every significant transaction
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