Seller financing tax: installment sale, recapture, and deferral

The short answer

Seller financing can turn a single taxable sale into a stream of payments. That does not make the gain disappear. It changes when part of the gain is taxed.

The general idea is:

1. Calculate the gross profit on the sale.
2. Divide it by the contract price to get the gross profit ratio.
3. Multiply each principal payment by that ratio to find the taxable gain for the year.
4. Report interest separately as ordinary income.
5. Account for depreciation recapture and other rules that are not spread over time.

The seller financing calculator estimates the closing-year tax, the yearly schedule, the cash-sale comparison, and the present value of the deferral. It is an educational model, not a tax return.

Start with basis and gross profit

The gain on a rental sale is not simply the price minus the original purchase price. The seller needs the adjusted basis, which generally starts with the purchase price and is adjusted for improvements, depreciation, and other items.

A simplified view:

Adjusted basis = original basis + capital improvements − depreciation taken

The amount realized is the sales price minus selling expenses. For an installment sale, the contract price and the gross profit are used to determine how much gain is reported each year.

The calculator uses this structure:

Installment basis = adjusted basis + selling expenses + depreciation recapture

Gross profit = purchase price − installment basis

Gross profit ratio = gross profit ÷ contract price

The recapture is separated because it is generally taxed in the year of sale rather than spread over the note.

Depreciation recapture is the accelerated piece

Residential rental property is depreciated over 27.5 years. When the property is sold, some or all of the depreciation may be recaptured.

For residential rental real estate, the unrecaptured section 1250 gain is generally taxed at a maximum rate of 25%. The exact amount depends on the depreciation taken, the sale price, and the taxpayer’s situation.

The important modeling point is timing: recapture is generally recognized in the year of sale, even if the rest of the gain is deferred. A seller who focuses only on the installment note can be surprised by a tax bill at closing.

The calculator’s default example has:

• Adjusted basis: $210,000
• Depreciation recapture: $25,000
• Selling costs: 3% of the price
• Cash-sale tax: about $12,468
• Tax at closing with seller financing: about $7,494

The difference is not a permanent tax saving. It is tax that may be paid later as principal is received.

Interest is taxed differently from gain

The note has two streams:

• Principal: returns the seller’s capital and triggers gain according to the gross profit ratio.
• Interest: compensation for lending money and generally taxed as ordinary income.

Interest is not capital gain. If the seller is in a high ordinary-income bracket, the interest can be taxed at a higher rate than the deferred long-term capital gain. That can make a high-rate seller note less attractive after tax than it looks before tax.

The calculator applies the ordinary income rate to interest, the capital gains rate to gain, the recapture rate to recapture, and an optional state rate to both. It also offers a 3.8% net investment income tax toggle for sellers who may be subject to NIIT.

NIIT and state tax

The net investment income tax is a 3.8% tax on certain net investment income above the applicable threshold. It can apply to capital gains, interest, and other investment income. The rules are fact-specific.

State tax is modeled as a flat rate. Real states have different rules for installment sales, recapture, and nonresident withholding. A flat state rate is a rough estimate, not a state return.

The calculator intentionally excludes:

• State-specific apportionment and withholding.
• Local taxes.
• Alternative minimum tax.
• Passive activity loss limitations.
• At-risk rules.
• 1031 exchange treatment.
• Principal-residence exclusions.

Those items can change the answer materially.

Assumed debt and wraps

The calculator assumes the buyer takes the property subject to a new seller note and does not assume an existing loan. That matters because debt relief can be treated as a payment in an installment sale.

If the buyer takes over an existing mortgage, wraps the property, or buys subject to an existing loan, the seller may have taxable gain earlier than the cash received. Those structures need separate legal and tax analysis. The calculator does not model them.

Cash sale vs. installment sale

A cash sale gives the seller liquidity and a known tax bill. An installment sale gives the seller a note, interest income, and deferral.

The comparison should include:

• Cash at closing: what the seller can reinvest now.
• Total tax: the undiscounted tax over the life of the note.
• Present value of tax: the tax bill discounted for timing.
• Interest income: the note’s yield.
• Credit risk: the buyer’s ability to pay.
• Balloon risk: the buyer’s ability to refinance.
• Liquidity: the seller’s ability to sell or borrow against the note.

A simple total-tax comparison can be misleading. Paying $12,468 now and $0 later is not the same as paying $7,494 now and $4,974 later, even if the undiscounted total is the same. The timing matters.

The calculator discounts the future tax at the rate you enter and reports a PV deferral benefit. A higher discount rate makes deferral look more valuable. That is a modeling choice, not a guarantee of after-tax return.

Worked example

Using the calculator’s default assumptions:

Item	Amount
Purchase price	$285,000
Adjusted basis	$210,000
Depreciation recapture	$25,000
Selling costs	3%
Gross profit	$41,450
Gross profit ratio	14.54%
Cash-sale tax	$12,468
Tax at closing with installment sale	$7,494
Tax deferred at closing	$4,974
Total interest tax over the note	$18,632

The seller does not receive the full $285,000 at closing. The seller receives the down payment, carries a $228,000 note, and pays tax as principal and interest come in.

The buyer’s economics are separate. The buyer needs to cover the note payment from the rent, maintain the property, and refinance the balloon. A tax-efficient seller structure does not fix a weak rental.

Questions to ask before choosing an installment sale

• What is the adjusted basis, and how much depreciation has been taken?
• Is any of the gain unrecaptured section 1250 gain?
• Will the buyer assume or wrap an existing loan?
• Is the note rate at or above the applicable federal rate?
• What are the state tax and withholding rules?
• Does the seller need liquidity before the balloon?
• What happens if the buyer defaults or refinances early?
• Is the seller eligible for installment treatment for this property?

The answers belong with a tax professional who can see the full return. The calculator is a way to ask better questions, not a substitute for the return.

The bottom line

Seller financing can defer part of the gain, but it also creates interest income, recapture at closing, credit risk, and a balloon. The after-tax comparison should use the time value of money, not just the undiscounted tax total.

Run the cash-sale case and the installment case in the seller financing calculator, then review the assumptions with a tax professional before signing the note.