When you sell a customer list, the proceeds are usually split for tax purposes: any gain matching amortization you previously deducted is recaptured as ordinary income, and the rest qualifies for long-term capital gain treatment. Whether the sale of a customer list produces capital gains or ordinary income depends on three things — whether you built the list or bought it, how long you held it, and whether you ever claimed amortization deductions against it. A self-created list that was never amortized can be entirely capital gain. A purchased list you have been writing off for years will almost always carry an ordinary-income component.
Start With Your Basis in the List
Your gain is the sale price minus your adjusted basis, so basis is where the analysis starts. It also drives the ordinary-versus-capital split, because recapture keys off amortization you have already taken.
If You Built the List
A customer list you developed internally through marketing, sales work, and relationship management almost always has a tax basis of zero. The costs of building it — advertising, employee pay, data management — were deducted as ordinary business expenses in the years you incurred them.1Office of the Law Revision Counsel. 26 U.S.C. 162 – Trade or Business Expenses Nothing is left to offset the sale price, so every dollar you receive is gain.
A self-created list also sits outside Section 197 amortization. The code excludes self-created intangibles from Section 197 unless they were created in connection with a business acquisition.2eCFR. 26 CFR 1.197-2 – Amortization of Goodwill and Certain Other Intangibles That matters here because if you never amortized the list, there is nothing for the recapture rules to grab. The entire gain flows through to Section 1231.
If You Bought the List
If you acquired the list in a prior deal, your starting basis is what you paid, or the amount allocated to the list if it was part of a larger acquisition. A customer list picked up in a business purchase is a Section 197 intangible, defined broadly enough to include “lists or other information with respect to current or prospective customers.”3Office of the Law Revision Counsel. 26 U.S.C. 197 – Amortization of Goodwill and Certain Other Intangibles You have been amortizing that cost over a mandatory 15-year straight-line schedule. Your adjusted basis is the original cost minus the amortization taken to date.
Every dollar of that prior amortization is a dollar the recapture rules will pull back into ordinary income when you sell.
How the Gain Splits Between Capital and Ordinary
Two provisions do the work: Section 1231, which supplies the capital-gain treatment, and Section 1245, which carves out the ordinary-income piece.
Section 1231 Sets the Favorable Baseline
A customer list held for more than a year and used in your trade or business is Section 1231 property. When your Section 1231 gains for the year exceed your Section 1231 losses, the net gain is taxed at long-term capital gain rates.4Office of the Law Revision Counsel. 26 U.S.C. 1231 – Property Used in the Trade or Business If losses exceed gains, the net is an ordinary loss, deductible without the annual caps that apply to capital losses.
There is a lookback that trips people up. If you claimed net Section 1231 losses in any of the prior five tax years, your current-year Section 1231 gain is recharacterized as ordinary income up to the amount of those unrecaptured losses. Check your last five returns before assuming the whole net gain gets capital treatment.
Section 1245 Pulls Prior Amortization Back to Ordinary
This is where sellers of purchased lists get surprised. Section 1245 says that when you sell amortizable property at a gain, the portion of the gain up to your cumulative amortization is taxed as ordinary income. Only what’s left qualifies for Section 1231 capital-gain treatment.5Office of the Law Revision Counsel. 26 U.S.C. 1245 – Gain From Dispositions of Certain Depreciable Property
A worked example makes the split concrete. You bought a customer list for $300,000 in a business acquisition and have claimed $100,000 in amortization, leaving an adjusted basis of $200,000. You sell for $350,000. Total gain is $150,000. The first $100,000, matching your prior amortization, is ordinary income under Section 1245. The remaining $50,000 goes into the Section 1231 netting and, absent offsetting losses, is a long-term capital gain.
For a self-created list with zero basis and no prior amortization, there is nothing to recapture. The full gain enters Section 1231 and typically comes out as long-term capital gain.
Aggregation When Multiple Intangibles Sell Together
If the customer list is sold alongside other Section 197 intangibles in the same transaction, all of them are treated as a single asset for recapture purposes.6Office of the Law Revision Counsel. 26 U.S.C. 1245 – Gain From Dispositions of Certain Depreciable Property – Section (b)(8) A loss on one intangible offsets a gain on another before recapture is calculated. Intangibles where basis exceeds fair market value are pulled out of the pool so those losses aren’t buried.
The Rates You Will Actually Pay
The ordinary-income portion — Section 1245 recapture or a five-year lookback amount — is taxed at your marginal rate, which can reach 37% for 2026. The capital-gain portion is taxed at long-term rates: 0% for taxable income up to roughly $49,450 for single filers ($98,900 for joint filers), 15% above that, and 20% for single filers above approximately $545,500 ($613,700 for joint filers).
A 3.8% surtax on net investment income kicks in for individuals with modified AGI above $200,000, or $250,000 for married couples filing jointly.7Office of the Law Revision Counsel. 26 U.S.C. 1411 – Imposition of Tax Those thresholds are not indexed for inflation and have held since 2013. Whether the surtax hits your customer-list gain depends on your involvement in the business. Gain from property held in a non-passive trade or business is excluded from net investment income, so a materially participating owner generally avoids the 3.8%. A passive owner generally does not.
State tax is the other piece. Most states tax capital gains as ordinary income, with rates from zero to over 13%, and nine states impose no tax on most capital gains. Run the combined federal and state numbers before you settle on a price.
Spreading the Gain Over Multiple Years
If the buyer pays over several tax years, the installment method lets you recognize gain as payments arrive rather than all at once.8Office of the Law Revision Counsel. 26 U.S.C. 453 – Installment Method Staying in lower brackets and deferring the cash to the IRS are the main reasons to use it. You calculate a gross profit ratio (total gain divided by total contract price) and apply it to each payment after subtracting the interest component.9Internal Revenue Service. Publication 537 (2025), Installment Sales
Two limits to know. Section 1245 recapture must be recognized in full in the year of the sale, no matter when payments arrive.10Office of the Law Revision Counsel. 26 U.S.C. 453 – Installment Method – Section (i) Only the gain above the recapture amount can be deferred. And if your outstanding installment obligations from the year exceed $5,000,000 in face amount, an interest charge applies to the deferred tax on the portion above that threshold.11Office of the Law Revision Counsel. 26 U.S.C. 453A – Special Rules for Nondealers
When the List Is Sold With the Business
If the customer list is one asset among many in a business sale, the total price has to be divided across everything transferred. That allocation drives how much gain you recognize on each asset and what character it carries.
The Residual Method
Section 1060 requires the buyer and seller to allocate the purchase price using the residual method, which fills seven asset classes in sequence up to fair market value, with any leftover falling into Class VII as goodwill and going concern value.12Office of the Law Revision Counsel. 26 U.S.C. 1060 – Special Allocation Rules for Certain Asset Acquisitions Customer lists sit in Class VI, which covers Section 197 intangibles other than goodwill. A written allocation agreement between buyer and seller binds both sides unless the IRS finds it inappropriate.
Both parties file Form 8594 with their returns for the year of the sale, and the IRS matches them.13Internal Revenue Service. About Form 8594, Asset Acquisition Statement Under Section 1060 Inconsistent filings invite audit. If an earnout or price adjustment changes the numbers later, an amended Form 8594 is required.
The Noncompete Trap
Business sales often include a covenant not to compete. For the seller, everything allocated to a noncompete is ordinary income, because it is payment for a personal service commitment. For the buyer, both the customer list and the noncompete amortize over the same 15-year Section 197 schedule, so the buyer is indifferent between the two labels while the seller is not.3Office of the Law Revision Counsel. 26 U.S.C. 197 – Amortization of Goodwill and Certain Other Intangibles Push allocation toward the customer list where the facts support it, because gain on the list can qualify for capital treatment while gain on the noncompete cannot. A noncompete also cannot be treated as disposed of or worthless until the entire business interest tied to it is sold, so there is no easy path to accelerate a loss on it later.
Putting the Pieces Together
Work through the answer in this order. Identify whether you built the list or bought it. If you bought it, pull your cumulative amortization; that number is your ordinary-income floor under Section 1245. Check the last five years for net Section 1231 losses that would recharacterize part of this year’s gain. Apply your marginal rate to the ordinary portion and the long-term capital gain rate to the rest, add the 3.8% surtax if it applies, and layer on state tax. If the buyer is paying over time, decide whether installment treatment is worth it given that recapture still lands in year one. If the list is bundled with a business sale, negotiate the Section 1060 allocation with the character consequences of a noncompete clearly in mind.