If you have looked into using a HELOC to pay off your mortgage faster, you have probably seen the first step: borrow a chunk from the line of credit and put it toward mortgage principal. That part makes sense. The question most people are left with is the next one.
How does the HELOC itself get paid off?
Short answer: the HELOC gets paid down in two ways. First, your monthly cash flow (income minus expenses) stays in the line and lowers the balance. Second, because your paycheck goes into the HELOC and sits there before you spend it, the daily balance stays lower, which reduces interest so more of your money goes to principal. Once the HELOC is paid back down, you repeat the cycle with another chunk.
Way 1: Your cash flow pays it down
Cash flow is simply what is left after your bills, debts, and living costs.
For example, if your household brings home $10,000 a month and spends $8,000 on everything, your cash flow is $2,000 a month. When your paycheck goes into the HELOC and only your actual expenses come out, that $2,000 stays behind. The balance drops by that amount, month after month.
That alone does not explain why this is different from sending $2,000 extra to the mortgage. The second way does.
Way 2: Lower daily balances cut the interest
A traditional mortgage generally charges interest based on the balance at the end of the month. A HELOC usually charges interest on the daily balance, or the average daily balance over the billing cycle.
That means timing matters. When your full paycheck lands in the HELOC, the balance drops that same day. You pay bills and your credit card statement from the line later, so for much of the month the balance is lower than it would otherwise be.
I recorded a YouTube video that gives you a full visual illustration of this. You could watch it here: https://youtu.be/ShHuplVfZwc
In the video, I walk through a small example: a $10,000 balance at 6%, a $5,000 monthly income paid on the 1st and 15th, and the same $9,000 ending balance on both a mortgage and a HELOC. The mortgage charged about $45 of interest for the month. The HELOC charged about $32.53, because the balance was lower for most of the month. Same rate, same starting balance, same ending balance. Lower interest.
The interest you did not pay is money that stays in the line and goes toward principal. Over time that creates a snowball effect.
If you want a deeper look at the two interest methods, read Mortgage Interest vs HELOC Interest.
Why the credit card matters
You might wonder who pays all their expenses in one shot at the end of the month. The answer is a credit card used for everyday spending and paid in full every statement.
- Gas, groceries, dining, and other everyday costs go on the card.
- When the statement is due, you draw from the HELOC and pay it in full, so you owe no card interest.
- Bills that cannot go on a card get paid from the HELOC as needed.
This delays the money leaving the HELOC and keeps the daily balance lower for longer. It only works if you pay the full statement balance. Carrying a card balance would wipe out the benefit.
What the cycle looks like
- Use a chunk of the HELOC to pay down mortgage principal.
- Run your paychecks through the HELOC and let your cash flow pay it back down.
- When the HELOC is back near where you started, use another chunk against the mortgage.
- Repeat until the mortgage is gone, then pay off the HELOC.
How big each chunk should be depends on your cash flow and your comfort level. My post on how to budget around a HELOC payoff plan walks through how to give every dollar a job.
What can slow it down
- Negative or thin cash flow. If expenses eat most of your income, there is little left to pay down the line.
- Variable rates rising. Most HELOCs are variable. A higher rate means more interest per day.
- Lifestyle creep. Available credit is not extra income.
- The wrong HELOC. Fees, draw limits, or unusual interest methods can work against you. See HELOC Rates Are Over 8%. Is It Still Worth It? for how rate and cash flow interact.
FAQ
How does a HELOC get paid off in the Accelerated Payoff strategy? Through your monthly cash flow staying in the line, plus lower daily balances that reduce interest so more of your money reduces principal.
Is this just using debt to pay off debt? Technically you are moving debt, but the HELOC's daily balance interest and your cash flow work together to pay it down faster than the mortgage would on its own.
How long does it take to pay back each HELOC chunk? It depends on the size of the chunk and your monthly cash flow. A larger surplus pays it back faster.
What if my HELOC rate is higher than my mortgage rate? It can still work in many cases because the interest is based on a lower daily balance, not the full mortgage balance. Run your own numbers first.
See the full strategy step by step
If you want to see how the whole cycle works with real numbers, join our free webinar. We walk through how the HELOC gets paid down and how families use it to pay off their mortgage faster.