Seller Financing Installment Sale Calculator 2026
Seller financing under IRS Section 453 lets sellers spread capital gains across years instead of recognizing all at sale. Combined with interest income on the carryback note, this can lower lifetime tax 5-15% vs all-cash sale. This tool models the full spread.
How Section 453 Installment Sales Work
Seller carries back a note instead of receiving all cash. Each principal payment recognizes a proportional share of capital gain ((principal payment ÷ sale price) × total gain). Spread across the note term, this can keep you in lower 0%/15%/20% LTCG brackets vs jumping to 20% by recognizing all gain in one year.
Recapture Limits the Strategy
Depreciation recapture (Section 1250 for real estate, 25% rate) cannot be deferred via installment sale — fully recognized in year of sale. This often eats much of the deferral benefit for rental property sellers. Plan for this cash outflow in year 1 even though most principal comes later.
Note Risk and Mitigation
Buyer default is the main risk. Mitigate with (1) 20%+ down payment, (2) deed of trust / mortgage securing the property, (3) due-on-sale + acceleration clauses, (4) personal guaranty if buyer is an entity, (5) shorter balloon term (5-10 years) to limit exposure. Most installment sales convert to all-cash within 5-7 years via refi.
Source: IRS Publication 537 (Installment Sales), IRS Section 453. Last updated: May 2026.