Buying a home subject to an existing mortgage means taking ownership by deed while the seller’s original loan stays in place, unpaid and still in the seller’s name. The buyer controls the property and makes the monthly payments; the lender’s records never change. The attraction is obvious when the seller’s loan carries a lower rate than anything available today, and the buyer avoids qualifying for new financing. The risks are just as real: the lender can demand full repayment at any time, and the seller remains personally liable for a debt someone else is now servicing.
How the Transfer Works
In a conventional sale, the buyer gets a new loan, the seller’s mortgage is paid off at closing, and both sides walk away clean. A subject-to deal skips the middle step. The seller signs a deed transferring ownership, that deed is recorded in the county land records like any other transfer, and the mortgage sits exactly where it was. Loan balance, interest rate, monthly payment, and escrow account all remain tied to the seller’s name and Social Security number.
The buyer now holds legal title, but the lender’s lien remains attached to the land. That lien does not care whose name is on the deed. If the payments stop, the lender forecloses on the property regardless of who owns it. Protecting the buyer’s ownership means keeping the seller’s loan current, month after month, indefinitely.
The arrangement works because property law broadly supports an owner’s right to transfer real estate. Nothing in a standard mortgage contract makes the deed itself void. The due-on-sale clause gives the lender a right to respond; it does not undo the transfer. The deed is valid, the buyer is the legal owner, and the loan simply has not gone anywhere.
Not the Same as a Loan Assumption
These two concepts sound alike and produce very different outcomes. In a formal loan assumption, the buyer applies to the lender, passes a credit check, signs an assumption agreement, and takes personal liability for the debt. The lender charges a fee, approves the transaction, and may release the seller from the note depending on the terms.
In a subject-to transaction, none of that happens. The lender is not contacted, no approval is sought, and the buyer never signs the promissory note. The buyer has no contractual relationship with the lender at all. That means the lender cannot pursue the buyer personally if payments stop — but it also means the seller stays fully liable. The seller’s name remains on the note, the loan continues to appear on the seller’s credit report, and any default lands on the seller’s record.
The practical difference is who bears the risk of default. With an assumption, the buyer carries it. With a subject-to purchase, the seller carries it, even though someone else is making the payments and living in the house.
The Due-on-Sale Clause
Nearly every residential mortgage written in recent decades contains a due-on-sale clause. The standard Fannie Mae uniform instrument states that if all or any part of the property, or any interest in it, is sold or transferred without the lender’s prior written consent, the lender may require immediate payment of the entire remaining balance.1Fannie Mae. Florida Mortgage – Section: 19. Transfer of the Property or a Beneficial Interest in Borrower That is acceleration: the full loan becomes due at once.
Lender authority to enforce these clauses rests on federal law. The Garn-St. Germain Depository Institutions Act of 1982, codified at 12 U.S.C. 1701j-3, preempts state laws that would restrict enforcement of a due-on-sale provision.2Office of the Law Revision Counsel. 12 USC 1701j-3 – Preemption of Due-on-Sale Prohibitions Before 1982, some states limited or banned these clauses. The federal statute settled the question nationally.
In practice, many lenders do not immediately invoke the clause when they discover a transfer, especially when payments are current. Acceleration is discretionary, not automatic. Relying on that inaction is a gamble, not a strategy. Market conditions change, loan servicers change, and a new servicer reviewing a file may take a different approach than the one that was content to collect payments.
Transfers That Do Not Trigger Acceleration
The same federal statute carves out specific transfers where a lender cannot accelerate on residential property with fewer than five dwelling units. These include a transfer by operation of law when a joint tenant or spouse holding by the entirety dies; a transfer to a relative on the borrower’s death; a transfer to the borrower’s spouse or children; a transfer resulting from a divorce decree, legal separation agreement, or property settlement; a transfer into a living trust where the borrower remains a beneficiary and occupancy does not change; the addition of a subordinate lien that does not involve transferring occupancy; and a lease of three years or less with no purchase option.2Office of the Law Revision Counsel. 12 USC 1701j-3 – Preemption of Due-on-Sale Prohibitions
A standard subject-to sale between unrelated parties does not fit any of these categories. The living-trust exemption is sometimes promoted as a workaround: transfer the property into a trust where the borrower remains a beneficiary, then later change the trust beneficiary to the buyer. The first step is protected. The second is not, and lenders who discover it can still accelerate.
What the Buyer Is Taking On
The biggest risk is acceleration. If the lender invokes the due-on-sale clause, the buyer faces a demand for the full balance, often hundreds of thousands of dollars, with no established right to negotiate. The buyer would need to refinance quickly, pay the balance in cash, or lose the property to foreclosure. Anyone entering a subject-to deal needs a realistic plan for that scenario before closing.
The buyer also has no direct relationship with the lender, which creates practical problems. Servicers generally will not discuss account details with anyone other than the borrower of record. Getting payoff statements, checking the escrow balance, or resolving a payment dispute requires the seller’s cooperation or a signed authorization letting the servicer talk to the buyer.3Consumer Financial Protection Bureau. Borrower Authorization of Third Party
The seller’s financial life is also now the buyer’s concern. If the seller files for bankruptcy, the mortgage lender becomes a creditor in that proceeding, and the property securing the debt can be drawn in. If the seller picks up tax liens, judgments, or other debts, new liens may attach to the property even after the deed transfer, since public records still connect the seller to the house through the mortgage. Title insurance, where available for these transactions, typically lists the existing mortgage as an exception to coverage rather than insuring against it.
What the Seller Is Still Carrying
Sellers often do not fully appreciate the risk they are keeping until something goes wrong. The mortgage stays in the seller’s name, so every late or missed payment hits the seller’s credit report. The seller has no direct control over whether the buyer pays on time, yet the seller’s credit score absorbs the damage.
The loan also remains on the seller’s debt-to-income ratio. When the seller tries to buy another home or refinance something else, the new lender sees the existing mortgage as a current obligation. Some lenders may treat it like a rental and give partial credit for payments the buyer is making, but only with documentation, often at least a year or two of history. Qualifying for a new mortgage while the old one still shows up is significantly harder.
The worst case is default. If the buyer stops paying and the lender forecloses, the property is sold. If that sale does not cover the remaining balance, the original borrower may face a deficiency judgment for the difference, depending on state law. The seller signed the promissory note, and no agreement between buyer and seller changes the seller’s obligation to the lender. The lender was never a party to the subject-to deal and is not bound by it.
Sellers should insist on structural protections before signing anything: a written agreement requiring timely payments, verification rights to confirm those payments, and a clear remedy — such as the right to reclaim the property — if the buyer defaults. Routing payments through a third-party loan servicing company that forwards them to the lender creates a documented trail that protects both sides.
Tax Treatment
The IRS treats a subject-to sale as a completed disposition, and the tax math can surprise sellers who think they have not “really” sold because the loan was not paid off. The amount realized on the sale includes any debt the buyer takes on or takes the property subject to. Sell a house with a $200,000 mortgage balance for $30,000 in cash with the buyer taking title subject to the mortgage, and the amount realized is $230,000, not $30,000.4Internal Revenue Service. Property (Basis, Sale of Home, etc.) 3
This principle was established in Crane v. Commissioner, which held that mortgage debt included in a property transfer counts as part of the amount realized even when the seller never personally assumed the mortgage.5Justia US Supreme Court. Crane v Commissioner, 331 US 1 (1947) The Court reasoned that the economic benefit of transferring encumbered property is just as real as if the debt had been paid in cash.
The reporting rules follow the same logic. The IRS instructions for Form 1099-S state that when a buyer takes property subject to a liability, that liability is treated as cash and included in gross proceeds.6Internal Revenue Service. Instructions for Form 1099-S If the transaction runs through a closing agent or title company, they are generally required to file a 1099-S reporting the full amount. The seller then reports gain or loss using the full amount realized minus adjusted basis and selling expenses. The standard home-sale exclusion of $250,000 for single filers or $500,000 for married filing jointly may be available if the seller meets the ownership and use requirements.7Internal Revenue Service. Publication 523 (2025), Selling Your Home
Buyers should recognize that their cost basis in the property includes the mortgage balance they took the property subject to, plus any cash paid to the seller. That basis matters later when the buyer sells, refinances, or calculates depreciation on a rental.
Paperwork That Holds the Deal Together
A subject-to transaction requires careful documentation because the usual closing machinery — where a title company pays off the old loan and records a satisfaction of mortgage — never runs. The parties are building their own paper trail for a deal the lender does not know about.
The buyer needs to verify the loan before committing: exact principal balance, interest rate, monthly payment, escrow status, and whether the loan is current. Because the lender will only speak with the borrower, the seller must sign a third-party authorization form allowing the servicer to release account information to the buyer.3Consumer Financial Protection Bureau. Borrower Authorization of Third Party Getting this early matters. Without it, the buyer is relying entirely on the seller’s word.
The deed is the instrument that transfers ownership. A general warranty deed offers the strongest buyer protection because the seller guarantees clear title and the right to convey. A quitclaim deed transfers only whatever interest the seller has, with no guarantees. Faster, riskier. The deed should carry the full legal property description (lot and block, or metes and bounds), not just the street address, and should reference the existing mortgage by its original recording information.
A separate written agreement, sometimes called a subject-to addendum, spells out the terms between buyer and seller. It should cover the buyer’s obligation to make the mortgage payments, what happens if the buyer defaults, the seller’s right to verify payments, how insurance and property taxes will be handled, and what occurs if the lender invokes the due-on-sale clause. Both parties should have this reviewed by an attorney. The consequences of sloppy drafting land disproportionately on the seller.
After signing, the buyer records the deed with the county recorder. Recording fees and transfer taxes vary by jurisdiction. Recording puts the world on notice that ownership has changed and places the buyer in the chain of title. Insurance comes next: the existing homeowner’s policy was issued to the seller, and the insurer needs to know about the ownership change. Common approaches include adding the buyer as a named insured or loss payee while keeping the seller listed to satisfy the lender’s requirements. A lapsed policy means no coverage if the property is damaged, and the lender will likely notice an insurance cancellation even if it missed the deed recording.
When This Structure Actually Gets Used
Subject-to transactions are not mainstream, and most real estate agents and title companies are unfamiliar or uncomfortable with them. They show up in specific circumstances where conventional financing does not work.
One common scenario is a seller behind on payments or facing foreclosure who cannot sell through normal channels because the property is worth less than the loan balance. A subject-to deal lets the buyer take over a low-rate loan without the cost and qualification requirements of new financing. For the seller, it avoids a foreclosure on the record, assuming the buyer actually keeps paying.
Investors use subject-to purchases to acquire rental properties without tying up capital in down payments or taking on today’s interest rates. A seller with a 3.5% fixed-rate mortgage from a few years back is more valuable to the right buyer than a seller demanding cash at market rates.
These transactions are legal in all states, but the absence of lender involvement means fewer guardrails than a traditional closing. Both parties should work with an attorney who understands the structure. The seller in particular needs someone looking out for their interests, because the economics overwhelmingly favor the buyer. The buyer gets the property and the loan terms. The seller gets a promise and an ongoing liability.