If you want your house paid off sooner, two options come up again and again. One is refinancing into a 15-year mortgage. The other is keeping your current mortgage and using a HELOC payoff plan, what we call the Accelerated Payoff strategy. Both can shorten your payoff. They work very differently, and one of them can actually cost you more if your current rate is low.

Short answer: a 15-year refinance and a HELOC payoff plan can finish in a similar amount of time when you put the same cash flow behind them. In my numbers, a 15-year refinance came out slightly ahead when today's rate was lower than the rate the homeowner already had. When the homeowner already had a low rate, refinancing cost far more interest, and keeping the mortgage won. The biggest differences are your current rate, the closing costs, and flexibility: a 15-year loan locks in a higher required payment, while a HELOC plan keeps your money accessible. Your monthly cash flow does most of the work either way.

I explain why refinancing does not always save you money in my video:

Disclosure: I co-founded Accelerated Strategies, which teaches HELOC-based payoff strategies, and my brother and I also own Solvit Mortgage, a mortgage lender. Because we have a stake in this topic, I am showing my assumptions and the cases where the HELOC plan does not win.

How each option works

A 15-year refinance

You replace your current mortgage with a new 15-year fixed loan. The rate on a 15-year loan is usually lower than a 30-year rate. As of November 5, 2026, Freddie Mac's weekly survey put the average 15-year fixed rate at 6.57%, compared with 7.18% for a 30-year fixed.

Higher required payment. You are paying the balance off in half the time.
Closing costs. A refinance is a brand new loan, with appraisal, title, and lender fees.
Locked in. Once you close, the higher payment is required every month, good months and bad.

A HELOC payoff plan

You keep your current mortgage and open a home equity line of credit. You use the HELOC to make chunk payments on your mortgage principal, then deposit your paycheck into the HELOC and pay your bills out of it. Your leftover cash flow pays the HELOC back down, and you repeat. I walk through the full routine in HELOC to Payoff Mortgage: Why Does It Work?

Your required mortgage payment does not change.
The line is usually variable. Bankrate's average HELOC rate was 7.49% as of November 4, 2026.
Your money stays accessible during the draw period.

A third option people forget

In a short video, I point out that you do not need a 15-year loan to pay like one. You can keep a 30-year mortgage and simply pay it on a 15-year schedule. If a month gets tight, you can scale back to the regular payment.

I included that option below, because it is the fairest comparison to a refinance.

I ran the numbers

Here is a straightforward illustration. These are hypothetical numbers, not a quote or a rate offer, and your results will be different.

The household: owes $300,000 at 7.00% with 28 years left. Current principal and interest is about $2,039 a month. They take home $10,000 a month and spend $5,000 on everything other than the mortgage, which leaves about $2,961 a month in cash flow.

My assumptions: a 15-year refinance at 6.57% with $6,000 in closing costs. A HELOC at 7.49% with a $30,000 limit, where income lands at the start of the month and spending goes out evenly through the month.

Test 1: The same extra $586 a month

The 15-year refinance raises the payment to about $2,625, or $586 more than today. To keep it fair, I gave every option that same $586.

Keep the mortgage, regular payment: about 28 years, about $385,045 in interest
15-year refinance: 15 years, about $172,478 in interest, plus $6,000 in closing costs, so about $178,478 total
Keep the 7% mortgage and pay $2,625 a month: about 15.75 years, about $195,835 in interest
HELOC plan with the same $586 a month: about 15.5 years, about $187,713 in interest

With the same small amount of extra money, the 15-year refinance came out ahead by roughly $9,000. That makes sense. The lower rate applies to the entire balance, and the HELOC plan cannot do much with only $586 a month of cash flow behind it.

Test 2: The household's full cash flow

Now let's put all $2,961 a month to work in each option.

15-year refinance plus the rest of the cash flow as extra principal: about 6.1 years, about $64,686 in interest, plus $6,000 in closing costs, so about $70,686 total
HELOC plan: about 6.2 years, about $67,557 in interest
Keep the 7% mortgage and send all of it as extra principal: about 6.25 years, about $70,319 in interest

Here all three land within about $3,000 of each other, and all of them turn a 28-year payoff into about 6 years. Even when I raised the HELOC rate by 2 points to 9.49%, the HELOC plan still finished in about 6.2 years with about $69,128 in interest. The tool mattered far less than the cash flow.

Test 3: When your current rate is low

Now say the same household owes $300,000 at 3.00% with 25 years left. Their payment is about $1,423, which leaves about $3,577 a month in cash flow.

Refinancing into a 15-year at 6.57% would cost about $172,478 in interest, more than the $126,790 they would pay by simply keeping the 3% loan for all 25 years, and that is before closing costs.
Keeping the 3% loan and paying $2,625 a month pays it off in about 11.2 years with about $53,741 in interest.
Keeping the 3% loan and using the full cash flow, extra payments and the HELOC plan both finished in about 5.5 years, with about $25,444 and $26,942 in interest.

If you already have a low rate, giving it up for a 15-year refinance at today's rates is usually a costly move. Keep the rate and put your cash flow to work.

Why I still like the HELOC plan for many families

The math in Test 2 was close. So the real question becomes: what happens when life does not go according to plan?

Your required payment stays the same. With a 15-year refinance, the higher payment is mandatory. If income drops, you still owe it.
Your money stays accessible. Extra principal payments are locked inside the house. Cash flow sitting in a HELOC can be drawn back out during the draw period. I cover this in Emergency Fund vs HELOC.
No refinance closing costs, and no reset. In my refinancing video, I show how refinancing deep into a loan can cost more interest overall, even at a lower rate, because you restart the most expensive part of the schedule.

There are real tradeoffs too. HELOC rates are usually variable, the lender can freeze or reduce a line, and the plan only works if you have positive cash flow and the discipline to stick with it. If a HELOC rate over 8% worries you, read HELOC Rates Over 8%: Is It Still Worth It?

Which one should you pick?

A 15-year refinance may fit you if:

Today's rate is meaningfully lower than your current rate
You want a fixed, forced plan and are comfortable with the higher required payment
You plan to stay long enough to recover the closing costs

A HELOC payoff plan may fit you if:

You already have a low rate you do not want to give up
You have steady positive cash flow and want to keep it accessible
You want flexibility if your income changes

Extra payments may be enough if:

You want the simplest option and do not need access to the money

If you want the side-by-side on extra payments, read Should I Make Extra Mortgage Payments? and All In One Loan vs HELOC vs Extra Payments.

FAQ

Is a 15-year refinance or a HELOC better for paying off a mortgage? It depends on your current rate and your cash flow. If today's rate is lower than yours, a 15-year refinance can save a bit more interest. If your current rate is low, keeping it and using a HELOC plan or extra payments usually wins. With strong cash flow, both can finish in a similar time.

See the full strategy, step by step

If you want to see how the HELOC payoff plan works with real examples, the risks, and how to tell if it fits you, join my free webinar. I walk through the math and answer the questions most people have before they start.

Watch the free webinar

Sources: Freddie Mac Primary Mortgage Market Survey, Nov 5, 2026 (source). Bankrate average HELOC rate, Nov 4, 2026 (source). Scenario math: my own monthly model, assumptions listed above.