A revolving mortgage is the informal name for a home equity line of credit, or HELOC: a credit line secured by your house that you can draw from, repay, and draw against again during a set window, paying interest only on the amount you’ve actually borrowed. Instead of handing you a single lump sum at closing, the lender sets a credit limit based on your equity and lets you pull funds as you need them. The home is collateral, which is why the rate sits well below what a credit card or unsecured personal loan would charge.
How the Credit Line Is Sized
The lender starts with your home’s current appraised value, subtracts the balance on your first mortgage and any other liens, and uses the remaining equity to set your limit. Most lenders cap total borrowing against the home at 85% of its appraised value when you add the HELOC to any existing mortgage debt, though some will go to 90% or higher. That ratio is your combined loan-to-value, or CLTV, and it is the main lever controlling how much credit you can access.
Your credit limit is a ceiling, not a target. You draw what you need, when you need it, and the unused portion costs nothing in interest. As you pay down the balance, that capacity comes back and can be borrowed again. The arrangement behaves much like a credit card in its mechanics, but it’s secured by real property and priced accordingly.
The Draw Period and the Repayment Period
Every HELOC runs in two distinct phases, and understanding the split is the single most important thing about how the product works.
The draw period comes first, lasting five to ten years in most agreements. During this window, you can access funds up to your credit limit, and your minimum monthly payment covers only the interest on whatever you’ve borrowed. That keeps monthly obligations low. It also means the principal balance doesn’t shrink unless you voluntarily pay more than the minimum.
Once the draw period ends, the repayment period begins and commonly runs ten to twenty years. New draws stop entirely. Payments shift from interest-only to fully amortized installments that pay down the principal over the remaining term. The monthly payment can jump sharply at this transition, sometimes doubling or more depending on the outstanding balance and the current rate. Building that future payment into your budget from the day you open the line is the best way to avoid trouble when the switch happens.
How the Interest Rate Works
Nearly every HELOC carries a variable rate, calculated by adding a fixed margin to a benchmark index. The benchmark is almost always the prime rate as published in the Wall Street Journal, which stood at 6.75% as of early 2026.1Federal Reserve Bank of St. Louis. Bank Prime Loan Rate (DPRIME) Your lender adds a margin based on your credit profile and CLTV. A strong borrower might see a margin near 0.5%; higher-risk borrowers could face 2% to 3% or more. The industry average sits around 0.75%.
Most agreements include a lifetime rate cap that limits how high the rate can ever climb no matter what prime does. Caps are often set high, sometimes 18% or more, so they function as an absolute ceiling rather than a comfort. Some lenders also offer introductory “teaser” rates for the first six to twelve months that revert to the standard variable rate when the promo period closes. The long-term cost of a HELOC is driven by the margin and the cap, not the teaser.
Fixed-Rate Conversion Options
Some lenders offer a hybrid feature that lets you lock a fixed rate on part of your outstanding balance while keeping the rest variable. You might lock $30,000 of a $75,000 balance at a fixed rate and continue drawing against the remaining $45,000 at the variable rate. Lenders that offer this typically allow two to five active fixed-rate segments at once, with minimum lock amounts of $5,000 to $10,000. Some charge a fee per conversion; others include a certain number of free locks each year. The locked portion converts to a principal-and-interest payment, so your monthly bill rises on that segment in exchange for predictability.
What It Takes to Qualify
Lenders look at three things: equity, credit, and debt load. You’ll generally need a FICO score of at least 680, with 720 or above getting the best pricing. Enough equity matters too. If your existing mortgage already accounts for 85% or more of the home’s value, there may not be room to establish a meaningful credit line.
Your debt-to-income ratio is the third gatekeeper. Lenders add the estimated HELOC payment to your other monthly obligations and divide by gross monthly income. Each lender sets its own ceiling, but the range generally falls between 43% and 50%.
Costs and Fees
HELOCs involve several costs beyond the interest rate. Closing costs can include an appraisal (commonly $650 to $1,150), a title search, and government recording fees. Many lenders waive some or all of these to win your business, but check the fine print: some recapture waived costs if you close the line within two or three years.
Annual maintenance fees for keeping the line open—even with a zero balance—range from as little as $5 to as much as $250 depending on the lender. A cancellation or early-termination fee may apply if you close the account within the first few years. Transaction fees, inactivity fees, and minimum draw requirements also appear in some agreements. Ask the lender for a complete schedule of every possible charge before signing.2Consumer Financial Protection Bureau. What Fees Can My Lender Charge if I Take Out a HELOC
Risks Worth Understanding Before You Borrow
A HELOC puts your home on the line. If you default, the lender can accelerate the debt and pursue foreclosure.3Consumer Financial Protection Bureau. What Is a Home Equity Line of Credit (HELOC) Three particular pressure points deserve attention.
Payment Shock at the Transition
The shift from interest-only payments during the draw period to fully amortized payments afterward is where most borrowers get into trouble. If you’ve been paying $200 a month on $50,000 in draws and suddenly owe $500 or more when principal kicks in, that jump can strain a household budget that was already tight. The risk compounds if rates have risen in the meantime.
Variable Rates in a Rising Market
Because HELOC rates track the prime rate, a rising-rate environment directly increases your cost of borrowing. The lifetime cap offers protection in theory, but when caps sit near 18% they are a backstop against disaster, not a buffer against higher payments.
Credit Line Freezes and Reductions
Federal rules allow your lender to freeze or reduce your available credit under several conditions: if your home’s value drops significantly below the appraised value at opening, if the lender reasonably believes you can no longer meet repayment because of a material change in your finances, or if you default on a material term.4Consumer Financial Protection Bureau. Regulation Z – 1026.40 Requirements for Home Equity Plans A housing downturn can trigger a formal review through an automated valuation model, a broker price opinion, or a new appraisal, and if your CLTV has climbed above the lender’s threshold the line can shrink or freeze without warning. If you’re planning to rely on a HELOC as an emergency reserve, understand that access is not guaranteed in the moments you may need it most.
When HELOC Interest Is Tax Deductible
Interest on a HELOC is deductible only if you use the borrowed funds to buy, build, or substantially improve the home that secures the line. A kitchen remodel or a new roof qualifies. Paying off credit cards or funding a vacation does not, even though the same house secures the debt.5Internal Revenue Service. Real Estate (Taxes, Mortgage Interest, Points, Other Property Expenses) 2
There is also a dollar cap. For debt taken on after December 15, 2017, deductible mortgage interest applies only to the first $750,000 in total acquisition debt ($375,000 if married filing separately). That limit covers your primary mortgage and any qualifying HELOC balance combined, not $750,000 each.6Internal Revenue Service. Publication 936 – Home Mortgage Interest Deduction Debt incurred before that date may still qualify under the older $1 million limit. You must itemize to claim the benefit.7Office of the Law Revision Counsel. 26 USC 163 – Interest
HELOC vs. Home Equity Loan
These two products are frequently confused, and the differences matter. A home equity loan hands you a single lump sum at closing, usually at a fixed rate, and you begin making principal-and-interest payments immediately on the full amount. A HELOC gives you a credit line you draw from over time, usually at a variable rate, with interest-only minimums during the draw period.8Consumer Financial Protection Bureau. What Is the Difference Between a Home Equity Loan and a Home Equity Line of Credit The revolving structure is the main reason to choose a HELOC; the fixed rate and fixed payment are the main reasons to choose a home equity loan.
Federal Protections and the Right to Cancel
Before you open a HELOC, Regulation Z requires the lender to give you detailed disclosures: how the rate is calculated, how payments will change between the draw and repayment periods, the conditions under which the lender can freeze or terminate the line, and a clear warning that you could lose your home if you default.4Consumer Financial Protection Bureau. Regulation Z – 1026.40 Requirements for Home Equity Plans Once the line is open, your periodic statements must show the outstanding balance, the current rate, and how finance charges were calculated for that billing cycle.9Consumer Financial Protection Bureau. Regulation Z – 1026.7 Periodic Statement
You also have a federal right of rescission. After signing, you can cancel the entire HELOC within three business days with no penalty. The clock starts on the latest of three events: the day you sign, the day you receive the required Truth in Lending disclosures, or the day you receive the notice of your right to rescind. During that window the lender cannot disburse funds or record a lien. To cancel, notify the lender in writing before midnight on the third business day; the lender then has 20 days to release any security interest and return any money you’ve paid.10Office of the Law Revision Counsel. 15 USC 1635 – Right of Rescission as to Certain Transactions If the lender never provided the required disclosures or the rescission notice, the cancellation window extends to three years from the date you signed.
What Happens When the Draw Period Ends
As the draw period winds down, you have several paths forward depending on your balance and finances:
- Pay off the balance. If you can manage it, bringing the balance to zero by the end of the draw period avoids the payment jump entirely, and most accounts simply close.
- Enter the repayment period. The default path. Payments switch to principal-and-interest over the remaining term, and new draws stop.
- Open a new HELOC. Some lenders let you roll the existing balance into a fresh line, resetting the draw period. This buys time but doesn’t eliminate the debt.
- Refinance into a home equity loan. Converting to a fixed-rate home equity loan gives you a predictable payment and removes the variable-rate risk, though the monthly amount may be higher than the interest-only minimums were.
- Roll everything into a new first mortgage. A cash-out refinance combines your primary mortgage and the HELOC balance into one new mortgage. This makes sense mainly if you can secure a competitive rate.
Start evaluating these options at least a year before the draw period expires. Refinances and new applications take time to process, and waiting until the final month leaves you with no leverage and fewer choices.