Real Estate Taxation, IRC Section 1031 Exchanges & Carryover Basis
IRC Section 1031 Like-Kind Exchange Boot & Basis Formula
Calculate IRC Section 1031 Real Estate Exchange Realized Gain ($M), Cash Plus Net Mortgage-Relief Boot under Treas. Reg. §1.1031(d)-2 ($M), Taxable Gain Recognized ($M), and Substituted Replacement-Property Tax Basis ($M).
Beware phantom "mortgage boot"—trading down debt triggers Section 1031 tax even with $0 cash taken!
To defer 100% of realized capital and depreciation-recapture gain under IRC Section 1031, a real estate investor selling a relinquished property via a Qualified Intermediary (QI) must BOTH reinvest 100% of net equity cash (Cash_Boot_Withdrawn = 0) AND replace all Paid-Off Mortgage Debt with equal or greater New Debt plus Fresh Cash Added! Under Treas. Reg. §1.1031(d)-2 Boot-Netting Rules, Cash Boot Withdrawn can NEVER be offset by taking on extra mortgage debt, while Net Mortgage-Relief Boot equals MAX(0, Old_Debt_Relieved - New_Debt_And_Fresh_Cash)—making Total Boot = Cash_Withdrawn + MAX(0, Old_Debt - New_Debt_Fresh_Cash), Taxable Gain Recognized = MIN(Realized_Gain, Total_Boot), and Substituted Replacement Basis = Replacement_Price - (Realized_Gain - Recognized_Gain)!
Verify on a Full-Deferral Multifamily Trade-Up—Relinquished_Net_Sale_Price = $5.00M (B2), Relinquished_Adjusted_Basis = $2.20M (B3 -> Realized Gain = $2.80M in E2), Old_Mortgage_Relieved = $3.00M ($2.00M QI escrow equity, B4), Cash_Boot_Withdrawn = $0.00M (B5), and New_Debt_Plus_Fresh_Cash = $4.50M ($6.50M replacement property price, B6): Total Boot Received is $0.00M (E3), Taxable Gain Recognized Today is $0.00M (E4), and Substituted Replacement Tax Basis is 6.50 - 2.80 = $3.70M (E5—embedding the $2.80M deferred gain cleanly inside the $6.50M property)!
| IRC §1031 Exchange Metric ($5.0M Sale, $2.2M Basis, $3.0M Old Debt -> $4.5M New Debt) | Formula | Verified Output |
|---|---|---|
| Realized Gain ($M) | MAX(0, Net_Sale_Price - Relinquished_Basis) | $2.80M |
| Total Cash + Mortgage Boot ($M) | Cash_Taken + MAX(0, Old_Debt - New_Debt_Cash) | $0.00M ($1.10M @ Trade-Down) |
| Taxable Gain Recognized ($M) | MIN(Realized_Gain, Total_Boot) | $0.00M ($1.10M @ Trade-Down) |
| Substituted Replacement Basis ($M) | Replacement_Price - (Realized - Recognized) | $3.70M ($2.20M @ Trade-Down) |
Section 1031 Boot-Netting & Taxable Gain Recognized Formula
Validate Sale_Price > 0, Basis >= 0, 0 <= Old_Debt < Sale_Price, 0 <= Cash_Withdrawn <= (Sale_Price - Old_Debt), and New_Debt_Fresh_Cash >= 0!
=LET(sl_p, B2, bs_0, B3, db_0, B4, cs_b, B5, db_1, B6, IF(OR(sl_p <= 0, bs_0 < 0, db_0 < 0, db_0 >= sl_p, cs_b < 0, cs_b > sl_p - db_0, db_1 < 0), "Invalid Sec 1031 Exchange Input", LET(rl_g, MAX(0, sl_p - bs_0), bt_t, cs_b + MAX(0, db_0 - db_1), ROUND(MIN(rl_g, bt_t), 2))))Trade-Down Phantom Mortgage-Boot Check ($0.30M Cash Out & $2.20M Smaller New Loan)
Simulate pocketing B5 = $0.30M cash from escrow AND stepping down new debt to B6 = $2.20M ($3.90M replacement property): Total Boot E3 jumps to 0.30 + (3.00 - 2.20) = $1.10M ($0.80M phantom debt-relief boot!), triggering $1.10M of immediate Taxable Gain E4 and setting Substituted Basis E5 to 3.90 - (2.80 - 1.10) = $2.20M!
=IF(ISTEXT(E4), E4, LET(rp_p, (B2 - B4 - B5) + B6, df_g, E2 - E4, ROUND(rp_p - df_g, 2)))Try the example
Use the original values or change them to test your understanding.