You are three years into a five-year fixed-rate mortgage at 3.5 percent. Current rates are 6.5 percent. You need to move for a new job, and you are dreading the conversation with your lender about breaking your mortgage and paying a prepayment penalty that could run into thousands of dollars. Then your mortgage broker mentions something you have never heard of: porting your mortgage. You can take your rate with you to the new house.
Porting a mortgage means transferring your existing mortgage from your current home to a new home when you move. You keep the same interest rate, the same remaining term, and the same lender. You avoid the prepayment penalty. You avoid refinancing at today’s higher rates. Porting is not available on every mortgage, and it is more common in Canada and the United Kingdom than in the United States, but it is one of the most valuable features a mortgage can have when rates are rising.
What Mortgage Porting Actually Is
Porting is the process of moving an existing mortgage from one property to another. The mortgage is not paid off and replaced with a new loan. It is transferred. The loan balance, the interest rate, the remaining amortization period, and the prepayment terms all stay the same. The only thing that changes is the property that secures the loan. The lender releases the lien on the old property and places a new lien on the new property.
Porting is not a right. It is a feature offered by some mortgages and not by others. Fixed-rate closed mortgages are the most commonly portable mortgages. Variable-rate mortgages and open mortgages are less commonly portable. In the United States, most conventional mortgages are not portable. In Canada, portability is a standard feature of most fixed-rate closed mortgages from major lenders. In the United Kingdom, porting is common but subject to the lender’s approval and a new affordability assessment.
When you port a mortgage, you are not breaking your existing contract. You are amending it to substitute a new property as security. Because you are not breaking the contract, you do not pay a prepayment penalty. This is the primary financial benefit of porting. You avoid the penalty that would apply if you paid off the mortgage early and took out a new loan at current rates.
How the Porting Process Works Step by Step
First, you check whether your mortgage is portable. Look at your mortgage contract or contact your lender. The portability feature will be stated in the mortgage terms. If your mortgage is portable, the lender will tell you the conditions that apply: the timeframe for completing the port, any fees, and whether you can increase the loan amount if the new property costs more than the old one.
Second, you sell your current home and buy a new home. The sale and the purchase should close on the same day or within a short window specified by the lender, typically 30 to 120 days. The lender will not release the lien on your old property until the new property is ready to secure the loan. If there is a gap between the sale closing and the purchase closing, the lender may require bridge financing to cover the gap.
Third, the lender underwrites the new property. Even though you are keeping the same loan, the lender must approve the new property as collateral. The lender will order an appraisal of the new property to confirm its value. If the new property appraises for less than the loan amount, the lender may require you to reduce the loan balance with a cash payment. The lender will also review your current financial situation. Porting is not automatic. The lender can decline to port the mortgage if your financial circumstances have changed materially, such as a loss of income or a significant drop in your credit score.
Fourth, you handle any difference in the loan amount. If the new property costs more than the old property, you may need to borrow additional funds. Some lenders allow you to increase your mortgage at the time of porting, blending your existing rate with the current rate for the additional amount. This is called a blended rate or a blend-and-extend. If the new property costs less, the lender will apply the excess sale proceeds to reduce your loan balance. You may pay a partial prepayment penalty on the portion that exceeds your annual prepayment privilege.
Fifth, the lender releases the lien on the old property and registers a new lien on the new property. You continue making the same monthly payments you were making before. The mortgage continues on its original amortization schedule. The port is complete.
Porting vs. Breaking Your Mortgage
Breaking a mortgage means paying it off before the end of the term. The penalty for breaking a fixed-rate closed mortgage is typically the greater of three months’ interest or the interest rate differential, which is the difference between your contract rate and the lender’s current rate for the remaining term, multiplied by the remaining balance and the remaining time. When rates have fallen since you took out your mortgage, the interest rate differential can be enormous. When rates have risen, it may be zero or close to zero because the lender can relend the money at a higher rate.
Porting avoids the prepayment penalty entirely because you are not breaking the mortgage. You are moving it. The lender continues to receive the same interest payments from you. The lender has no loss to compensate for, so no penalty applies. This is why porting is most valuable when rates have risen. If you locked in at 3.5 percent and current rates are 6.5 percent, breaking your mortgage would incur no interest rate differential penalty because the lender can relend at a higher rate. But you would still lose your below-market rate. Porting preserves the rate and avoids whatever penalty might apply.
If rates have fallen since you took out your mortgage, breaking and refinancing may be cheaper than porting. You can pay the penalty, take out a new mortgage at a lower rate, and come out ahead over the remaining term. Porting preserves a high rate that you would be better off replacing. The decision to port or break depends entirely on the direction rates have moved since you took out your mortgage.
Porting in the United States
Most conventional mortgages in the United States are not portable. Fannie Mae and Freddie Mac, which purchase most conventional mortgages from lenders, do not offer a portability feature. FHA loans, VA loans, and USDA loans are not portable. If you have a conventional U.S. mortgage and you want to move, you must either pay off the mortgage from the sale proceeds and take out a new mortgage on the new home, or you must qualify to carry both mortgages simultaneously, which few borrowers can do.
A small number of portfolio lenders in the United States offer portable mortgages. Portfolio lenders are banks and credit unions that keep the loans they originate rather than selling them to Fannie Mae or Freddie Mac. Because they hold the loans on their own books, they can offer features that the secondary market does not support. If portability is important to you, ask local community banks and credit unions whether they offer portfolio mortgages with a portability feature.
Assumable mortgages are a related but distinct concept in the United States. An assumable mortgage allows a buyer to take over the seller’s existing mortgage when purchasing the home. FHA loans, VA loans, and USDA loans are assumable subject to lender approval. Assumability benefits the seller by making the home more attractive to buyers when rates are high. It does not benefit the seller directly because the seller is moving to a new home and needs a new mortgage. Porting would benefit the seller. Assumability benefits the buyer.
Frequently Asked Questions
Can I port any mortgage?
No. Portability is a feature of specific mortgages, primarily fixed-rate closed mortgages from Canadian and UK lenders. Most U.S. conventional mortgages are not portable. Check your mortgage contract for a portability clause, or contact your lender and ask whether your mortgage is portable. If you are shopping for a new mortgage and portability matters to you, ask about it before you sign.
What happens if the new house costs more than the old one?
You must cover the difference with additional funds. If you have a $200,000 mortgage and the new house costs $300,000, you need an additional $100,000 plus the down payment on the new home. You can use cash from the sale of your old home if you had equity, or you can borrow additional funds. Some lenders allow a blended rate: your existing $200,000 stays at your current rate, and the additional $100,000 is borrowed at the current market rate, with the two blended into a single payment.
What happens if the new house costs less than the old one?
The lender applies the excess proceeds to reduce your loan balance. You may pay a prepayment penalty on the portion that exceeds your annual prepayment privilege, typically 10 to 20 percent of the original loan amount. If your mortgage has a $200,000 balance and you are buying a $150,000 home, $50,000 of your loan balance must be paid down. If your annual prepayment privilege is $30,000, you pay a penalty on the remaining $20,000.
Does porting a mortgage affect my credit score?
No. Porting a mortgage is not a new loan application, although the lender will review your current financial situation. It does not appear as a new account on your credit report. It does not create a credit inquiry in the same way a new mortgage application does. The mortgage continues as the same account with the same opening date and the same payment history.
How long do I have to port my mortgage after selling?
The porting window is typically 30 to 120 days from the date your old home sells. You must close on the new home within that window. If you cannot close within the window, ask the lender for an extension before the window expires. If the window expires and you have not ported the mortgage, the lender treats the mortgage as paid off from the sale proceeds, and you lose the portability benefit. The prepayment penalty, if any, applies.
The Short Version
Porting a mortgage means taking your current rate and terms with you when you move to a new house. You avoid the prepayment penalty. You keep your below-market rate. You continue making the same payments to the same lender. The only thing that changes is the address on the loan documents.
Porting is common in Canada and the UK. It is rare in the United States, where most conventional mortgages are not portable. If you have a portable mortgage, port when rates have risen since you locked in. Break and refinance when rates have fallen. The portability feature in your mortgage contract is worth thousands of dollars when rates are moving up. Know whether you have it before you list your home for sale.
Last modified: June 10, 2026
