Selling Your Business: Tax Planning Before, During, and After the Transaction

A business sale is the largest financial event most owners will ever experience — and the decisions made in the 90 days before closing can cost or save hundreds of thousands of dollars in federal taxes alone. This guide covers the four levers that move the number: sale structure, QSBS exclusion, installment timing, and pre-close charitable strategy. It includes a tax estimator showing your estimated net after federal capital gains and NIIT.

Stock sale vs. asset sale: the first fork in the road

Most business sales are structured as one of two types. The tax treatment is radically different.

The bottom line: sellers almost always prefer a stock sale (single layer of LTCG tax). Buyers almost always prefer an asset sale (fresh basis for depreciation). The negotiated premium you may need to offer a buyer to accept a stock sale — typically 2–7% of purchase price — is often worth it once you run the after-tax math on your specific deal.

C-corps have an additional card to play in a stock sale: the Section 1202 QSBS exclusion. For LLC members and S-corp shareholders, that card doesn't exist, which is one reason some founders convert to C-corp status years before a planned exit.

The QSBS exclusion: eliminating up to $15M in capital gains

Section 1202 of the tax code — Qualified Small Business Stock — is the single most powerful tax break available to business owners. If your shares qualify, a portion or all of your capital gain can be permanently excluded from federal income tax.

Requirements for §1202 QSBS status

• C-corporation only. LLC interests and S-corp shares do not qualify. The business must be structured as a C-corp.
• Gross assets at issuance ≤ $75M (for stock issued after July 4, 2025) or ≤ $50M (for stock issued before July 5, 2025).¹
• Active business in a qualifying industry. Professional services (law, consulting, accounting, finance, health), hotels, restaurants, and a handful of others are excluded. Technology, manufacturing, and most other industries qualify.
• Stock acquired at original issuance (not secondary market purchase).
• Holding period: minimum 5 years for pre-OBBBA stock; as few as 3 years for stock acquired after July 4, 2025 (see tiered exclusion below).

Pre-OBBBA stock (issued on or before July 4, 2025)

The rules you've likely heard about: hold for at least 5 years and exclude 100% of your gain, up to the greater of $10 million or 10× your adjusted basis.¹ For most founders who invested a modest amount early on, $10M is the binding cap.

Post-OBBBA stock (acquired after July 4, 2025)

The One Big Beautiful Bill Act (P.L. 119-21, July 4, 2025) expanded §1202 for stock acquired after that date:¹

• 3-year hold: 50% of gain excluded
• 4-year hold: 75% of gain excluded
• 5-year hold: 100% of gain excluded
• Cap raised to $15 million per issuer (inflation-adjusted after 2026)
• Asset threshold raised to $75 million at time of stock issuance

The tiered holding period is the key new feature. An investor who holds post-OBBBA QSBS for only 3 years can still exclude half the gain — a major change from the prior all-or-nothing 5-year cliff. The non-excluded portion is taxed at LTCG rates plus NIIT.

Business Sale Tax Estimator

Estimate your federal capital gains tax under three scenarios: standard LTCG, pre-OBBBA QSBS (100% exclusion up to $10M), and post-OBBBA QSBS (tiered exclusion up to $15M). State taxes not included — add 0–13% depending on your state.

Installment sales: spreading the tax bill over years

If QSBS doesn't apply and the gain is large, an installment sale under IRC §453 is the next tool.² Instead of receiving the full purchase price at closing, you accept payments over 2–10 years. You recognize gain (and pay tax) only as you receive each installment.

When it works:

• The buyer can reasonably be expected to make payments — ideally secured by the business assets or a letter of credit
• You're currently in a high-income year (sale year) and expect lower income in future years, shifting some recognition to lower-bracket years
• The deal allows it — most private-equity buyers pay cash at close, but strategic buyers and individual buyers are often flexible

The math: If your business sells for $3M and your gain is $2.8M, a cash deal creates roughly $667K in federal tax in one year. A 5-year installment ($600K/yr principal) spreads $560K of annual gain recognition — potentially keeping you in the 15% LTCG bracket rather than the 20% bracket, saving roughly $130K+ in total.

The risk: If the buyer defaults, you've paid tax on payments you haven't received. Protect yourself with a security interest in the business assets, a personal guarantee, or a performance bond before agreeing to structured payment terms. Have an attorney draft the seller-financing note carefully.

Pre-close charitable strategies: DAF before you sign

If you're charitably inclined, the window between "we have a deal in principle" and "we've signed the purchase agreement" is the most valuable planning moment. Done correctly, contributing appreciated stock or LLC interests to a donor-advised fund (DAF) before close gives you:

1. A charitable deduction at the full fair market value of the contributed interest (not your basis)
2. Zero capital gains tax on the appreciation in the donated shares

The deduction is limited to 30% of AGI for non-cash contributions to a DAF, with a 5-year carryforward (IRC §170).³

Critical timing: The donation must occur before a binding purchase agreement is signed. The IRS "assignment of income" doctrine and "step transaction" doctrine will collapse the strategy if the sale is already effectively determined. Don't let your attorney or buyer tell you the deal is "done" before you make the contribution — work with your CPA to pin down the exact moment of commitment.

What to do with the proceeds

After closing, you have $1M–$5M liquid. Most business owners feel an immediate urgency to do something. The right move is often to do very little for 30–90 days.

Immediately after close

• Park the money safely. A combination of FDIC-insured accounts (up to $250K per bank per account type) and Treasury money market funds covers amounts above FDIC limits without market risk. Vanguard VMFXX or Fidelity SPAXX are reasonable options while you develop a plan.
• Don't make any large financial commitments. No real estate purchases, no business investments, no major gifts to family. The psychological pressure of sudden liquidity is real and well-documented — give yourself a 90-day decision pause on anything above $50K.
• Check tax-year timing. If you closed before December 31, your CPA should model whether any year-end moves (TLH elsewhere, Roth conversion, charitable contribution, retirement account maximization) reduce this year's bill.

Building the investment portfolio

Once you have a plan, your proceeds become a long-term investment portfolio. Key considerations at $1M–$5M:

• Asset location: which accounts (taxable, IRA, Roth) hold which asset classes matters enormously at this size. See our asset location guide.
• Direct indexing: above $250K–$500K in taxable accounts, direct indexing replaces an ETF with individual stocks and generates ongoing tax-loss harvesting. At $1M+ taxable, the math often favors it. See our direct indexing guide.
• Concentrated stock: if the business sale left you with stock in an acquiring company or earn-out shares, those are a new concentration risk. See our concentrated stock guide.
• Lump sum vs. DCA: academic research consistently shows lump-sum investing outperforms dollar-cost averaging in roughly two-thirds of historical scenarios (because markets trend up). But DCA reduces regret risk. Many business sellers compromise: invest 50% immediately, spread the rest over 6–12 months.

For a full allocation framework, see our how to invest $1 million guide.

The advisory team you need for a business sale

A business sale requires a team that works in coordination, not isolation. If any of these roles are missing, the gaps can be expensive.

The most common mistake: hiring the M&A team and ignoring the CPA and financial advisor until after the deal closes. By then, the QSBS window has closed, pre-close charitable opportunities have passed, and the installment sale structure has been locked into a cash deal. Many six-figure tax savings are only available before you sign.

Sources

1. Davis Wright Tremaine — QSBS Updates Under the One Big Beautiful Bill Act (2025); Perkins Coie — Significant Changes to §1202 Under OBBBA. For stock acquired after July 4, 2025: tiered exclusion (50%/75%/100% at 3/4/5-year hold), cap raised to $15M, asset threshold raised to $75M. For stock issued on or before July 4, 2025: prior rules apply (100% exclusion at 5-year hold, $10M cap). P.L. 119-21 enacted July 4, 2025.
2. IRC §453 — Installment Method (Cornell Law). Gain recognized proportionally as payments are received; deferred gain includes LTCG portion. Seller may elect out of installment method in the year of sale.
3. IRS — Charitable Contribution Deductions; IRC §170. Non-cash contributions to a donor-advised fund: deductible at fair market value up to 30% of AGI; 5-year carryforward for excess. Contribution of appreciated stock avoids capital gains recognition on the appreciation. Contribution must precede any binding commitment to sell.
4. Tax Foundation — 2026 Tax Brackets and Capital Gains Rates; Kiplinger — Capital Gains Tax Rates 2026. LTCG 0% threshold: $49,450 single / $98,900 MFJ. 20% threshold: $545,500 single / $613,700 MFJ. Net Investment Income Tax (IRC §1411): 3.8% on NII above $200K single / $250K MFJ. Values per IRS Rev. Proc. 2025-67. Verified May 2026.

QSBS rules reflect One Big Beautiful Bill Act (P.L. 119-21, July 4, 2025). Capital gains rates and NIIT thresholds reflect 2026 IRS inflation adjustments per Rev. Proc. 2025-67. This page does not constitute tax or legal advice — consult a CPA and M&A attorney before any business transaction.