If you can pay cash for a $5M home, paying cash is the simplest way to buy it: no lender, no monthly payment and no interest. Financing keeps several million dollars liquid and out of a single asset, in exchange for interest and a payment that has to be planned. Which matters more depends on your balance sheet, your horizon and what you want your capital to be doing.
Buying a house with cash buys certainty
Three things come with a cash purchase.
No payment. There is nothing to keep up with from month to month, no rate that can reset, and no lender with a claim on the home.
No interest. On a $4M loan over 30 years at an assumed 6.1%, the payment is $24,239.79 a month and the interest comes to $4,726,324.91. A cash buyer pays none of it. The rate here is an assumption for illustration, not an offer.
Fewer moving parts. There is one contract. There is no lender’s underwriting, no lender’s appraisal and no loan fee.
For some buyers that is the whole argument.
Cash is stronger in a negotiation
A financed offer usually depends on a lender’s decision and a lender’s appraisal. A cash offer depends on neither. For a seller that means fewer ways for the sale to fail, and often a faster closing. When several buyers want the same house, certainty can count for as much as price.
How much that is worth in dollars depends on the house and the market. Do not assume a set reduction in price for paying cash. What a cash offer reliably buys is the seller’s confidence that the sale closes.
A financed buyer can narrow the gap. You can complete full underwriting before you make an offer. You can shorten the financing contingency. Or you can buy with cash and borrow afterward.
Delayed financing lets you buy with cash and borrow afterward
Delayed financing means closing with cash, then taking a mortgage on the home soon after to recover the capital. You get the negotiating strength of cash and, later, the liquidity of a loan. The terms deserve a close read.
Fannie Mae’s rule is the usual reference point. A cash-out refinance normally requires at least one borrower to have been on title for six months. The delayed financing exception waives that wait when its conditions are met. Among them, the purchase was at arm’s length, the settlement statement confirms that no mortgage financing was used, and the source of the purchase funds is documented. The new loan can be no larger than your documented initial outlay plus closing costs, prepaid fees and points, and cash-out pricing applies.
One condition applies to buyers who raised the cash by borrowing elsewhere. If the purchase was funded with a loan against another asset, such as a line of credit on a different property, the proceeds of the new mortgage must go to paying that loan down.
That rule covers loans Fannie Mae buys. For 2026 those stop at $832,750 on a one-unit home in most of the country and $1,249,125 in high-cost areas. On a $5M home the loan you want is a jumbo, and jumbo lenders write their own delayed-financing terms: the waiting period, the maximum loan-to-value and the pricing.
Tax timing matters too. Under IRS Publication 936, a mortgage taken out within 90 days before or after you buy the home can be treated as home acquisition debt, up to the home’s cost. Outside that window, interest on a loan that was not used to buy, build or substantially improve the home is not deductible.
Cash costs you liquidity, concentration and sometimes tax
Liquidity. Once $5M is in the house, you reach it by selling the house or borrowing against it, at the rates available then, and only if you qualify then.
Concentration. A home is one asset on one street. A $5M home is 10% of a $50M net worth and more than 60% of an $8M net worth. The same purchase is a different decision in each case.
Tax on raising the cash. If the money is already in the bank, this does not apply. If you have to sell appreciated securities, the sale realizes a capital gain. The IRS taxes long-term gains at rates up to 20% for most assets, and a 3.8% net investment income tax can apply above certain income levels. Selling $5M of shares with a $2M cost basis produces a $3M gain and a federal tax bill of as much as $714,000, before state tax. That cost never appears on the closing statement.
What the capital might have earned. Capital in a home earns whatever the home appreciates, less taxes and upkeep. Capital kept outside it can be put to other work.
A decision that is hard to reverse. A mortgage can usually be paid down or paid off when you choose, subject to its prepayment terms. Cash already in the house comes back only if a lender agrees to lend against it later. Of the two choices, paying cash is the harder one to undo.
Financing keeps capital liquid, at the price of interest
Interest. On the same $4M loan, the first year’s interest is $242,666.92.
A deduction with a limit. IRS Publication 936 allows a deduction for interest on the first $750,000 of home acquisition debt taken out after December 15, 2017. That is a little under a fifth of a $4M loan. Your CPA can tell you what the after-tax rate is in your case.
The comparison that decides it. Financing comes out ahead in dollars when the capital you keep earns more than the loan rate, after tax, over many years. A household that keeps capital for a purpose, such as a business, an investment program or reserves, is paying interest for the use of that capital. The figure to compare is what the capital does for you against what the loan costs.
A payment that has to be planned. The payment is due every month for the life of the loan, and the lender holds a lien on the home. The financing that works is the financing whose payments have a planned source in every phase.
Some buyers borrow against a portfolio instead of the house. FINRA’s description of securities-based lines of credit sets out their terms: rates are typically variable, the line is tied to the market value of the account, a fall in that value can bring a maintenance call, and the lender may call the loan at any time. Buy, borrow, die and where the home fits covers that route.
| On a $5M home | Pay cash | Finance with 20% down |
|---|---|---|
| Capital at closing | $5,000,000 | $1,000,000 |
| Monthly payment | none | $24,239.79 |
| Interest over 30 years | none | $4,726,324.91 |
| Purchase capital left liquid | none | $4,000,000 |
| Lender involved | no | yes |
| What has to be managed | Liquidity and concentration | The payment and its source |
The financed column is a 30-year fully amortizing loan at an assumed 6.1%. Property taxes, home insurance and maintenance are the same in both columns and are left out. So are closing costs, which are higher with a loan.
A few facts about you change the answer
| If this is true | It leans toward |
|---|---|
| The home is a small share of your net worth | Cash |
| Paying cash would leave you with thin liquid reserves | Financing |
| Raising the cash means selling assets with large gains | Financing |
| The loan rate is above what you expect to earn with confidence | Cash |
| A business or other commitments may need the capital | Financing |
| You want the later payments planned at purchase, not left to future income | A structured plan |
Most of these are facts about you, not about the market. That is why two households with the same means can reasonably choose differently.
The choice is also not binary. A down payment of 40% or 50% cuts the interest and the payment and still leaves capital free. An interest-only jumbo mortgage lowers the early payment and schedules principal for the later years. Households with a family office tend to weigh all of these together, as how family offices finance a home describes.
Where The Family Office Mortgage fits among the options
Between all cash and 20% down there is a wide middle, and The Family Office Mortgage sits in it with a particular shape. Half the purchase price is committed up front: 20% as the down payment and 30% to a separately funded indexed universal life (IUL) insurance policy, with a bank financing part of the premiums. On a $5M home that is $2,500,000 at closing, against $5,000,000 for cash and $1,000,000 for a traditional loan.
The traditional mortgage was built for buyers who need to borrow as much of the price as they can. A buyer who could pay cash is in a different position. That buyer can commit more at closing and have the capital fund the home over time, without putting all of it into the house. Capital is the advantage. This is the structure that uses it.
In the $4M reference case you pay $16,266.67 a month, interest only, for fifteen years. From year 16 the scheduled payment is $27,176.61 a month, and projected policy cash of $370,000 a year is designed to fund it. The mortgage runs its full 30 years. Projected policy cash is designed to continue after the mortgage is repaid, through year 62 in the reference case. Three debts sit inside the plan, each on its own schedule: the mortgage, the bank’s premium-finance loan and policy loans.
What a cash buyer keeps is half the capital, liquid. What the plan adds is a designed source for the later payments, and a team that manages it. Every transaction is underwritten by the team before it is proposed, and each case is modeled under a conservative risk profile and run through simulations across many market paths. The plan is built with margin: illustrated policy cash of $370,000 a year against $326,119 of scheduled mortgage payments, so policy cash could come in 10% lower, at $333,000, and still cover every mortgage payment. After closing, policy values, the bank loan and the collateral are reviewed every year against the plan, so adjustments are made early.
The team has done hundreds of transactions, and your own CPA and attorney review the proposal before anything is signed. The comparison shows the full path, the calculator runs it on your price, and how the risks are managed covers the team’s part. When you want your own figures, see if you qualify.
