Could Transferable Mortgages Unfreeze Housing?

Experts discuss impact for agents, buyers and sellers

As mortgage-rate lock continues to freeze listings across the U.S., a growing number of homeowners are asking a once-niche question: “Why can’t I just take my 3% mortgage with me?”

Portable—or “transferable”—mortgages are common in Canada and the U.K., allowing borrowers to move their existing home loan (and below-market rate) to a new property. In theory, that would offer American homeowners a graceful exit from the rate trap: sell, buy again, keep your low rate.

But U.S. real estate economists, mortgage analysts, and securities experts caution that what sounds simple at the kitchen-table level becomes extremely complex inside the machinery of American housing finance. The result? A growing debate about whether portability is a breakthrough waiting to happen—or a disruption we’re not built to withstand.

Why Portability Is Suddenly a Hot Topic

Two forces have pushed this once-obscure idea into the mainstream conversation:

1. Historic Rate Lock Has Immobilized the Market

Roughly 80% of U.S. mortgage holders have a rate below 5%, and nearly one-third are below 3%. With today’s mortgage rates sitting significantly higher, homeowners are reluctant to trade a manageable monthly payment for one that jumps by hundreds—or thousands—of dollars.

A portable mortgage appears to offer a solution: keep your rate, move your life.

2. Housing Mobility Has Collapsed

People usually move every 7–10 years. Now? Many are holding tight—not because they love their home, but because they love their rate.
Policymakers and industry analysts are hunting for ways to improve mobility, and portability has re-entered the conversation as a potential lever.

Why Experts Say the U.S. System Isn’t Designed for It

The biggest obstacle isn’t consumer demand—it’s structural.

1. Portable Loans Would Disrupt the Mortgage-Backed Securities (MBS) Market

Unlike Canada and the U.K., the U.S. mortgage system relies heavily on the MBS market, where loans are pooled, securitized, and sold to investors worldwide.
These investors expect those loans to behave predictably—mature at a certain pace, prepay under certain conditions, and remain tied to the original collateral.

Portability breaks all three assumptions.

A loan that moves from one property to another becomes unpredictable. That uncertainty changes investor pricing models—and ultimately forces mortgage rates higher to compensate.

2. Portability Doesn’t Eliminate the Real Affordability Gap

Even if portability were allowed, it wouldn’t magically solve affordability.
Here’s why:
You only “port” the remaining balance, not the new home’s price.

Example:

• Current mortgage balance: $280,000 at 3%

• New home price: $700,000

• You still need a new $420,000 loan at today’s rates

Portability softens payment shock—it doesn’t erase the math of higher home prices.

3. It Could Add Layers of Complexity for Agents and Lenders

In markets where portability exists, contract timelines, appraisal conditions, lender approvals, and transfer windows can complicate otherwise straightforward transactions.

Agents must become fluent in a more technical financing landscape—adding friction in a market already dealing with appraisal gaps, inspection renegotiations, and contingent deals.

4. Secondary Market Players May Not Want It

Fannie Mae, Freddie Mac, and MBS investors control the real levers.
If they can’t price the risk, portability never makes it out of theory and into practice.

Why Some Support the Idea Anyway

Despite the hurdles, proponents argue portability could help the market breathe again—especially for:

• Lateral movers staying in the same price band

• Downsizers seeking flexibility

• Homeowners needing to relocate for work

• Sellers who would move if not for their golden-rate handcuffs

Even a modest release of listings could improve inventory conditions in markets like Denver, where move-up buyers remain locked between high rates and high prices.

What It Means for Denver Homeowners Right Now

The Denver Metro market faces the same national pressures: strong demand, tight inventory, and affordability challenges. While portable mortgages offer a compelling thought experiment, the structural barriers mean change is unlikely in the near term.

So for now, unlocking mobility relies on strategies available today:

• Temporary and permanent rate buydowns

• Seller concessions

• Restructured financing

• Creative deal architecture

• Negotiation strategies tailored to the rate environment

Portability may someday become part of the conversation—but in 2025, buyers and sellers need solutions that function within the existing system.