Both the financing guide and the becoming a landlord article mention this move without ever actually explaining it: using equity in your first house to fund the down payment on a second one. Here’s the piece that was missing, what a HELOC and a cash-out refinance actually are, how they differ, and a third option that neither of those articles named, one that doesn’t touch your primary home at all.
Short version: a HELOC leaves your existing first mortgage untouched and adds a separate, variable-rate line on top of it. A cash-out refinance replaces your entire first mortgage with a new, larger one at today’s rate. The single biggest factor in choosing between them is whether your current mortgage rate is above or below what’s available today, get that backwards and you could give up a rate worth tens of thousands of dollars over the life of the loan. Both put your primary residence up as collateral for a bet on a completely different property, a real risk most comparisons gloss over. And if you already own a rental, a DSCR cash-out refinance on that property specifically can raise the same cash without your primary home ever entering the picture.
The Real Question First: What’s Your Current Mortgage Rate?
Before anything else, this is the number that actually decides which direction makes sense. A cash-out refinance doesn’t just add debt, it replaces your entire existing mortgage with a new one at whatever rate is available today. If you bought or refinanced between 2020 and 2022 and locked in something in the 2.5-5% range, a cash-out refinance means giving up that rate on your entire remaining balance, not just the new money you’re pulling out. Left unaddressed over a full 30-year term, that gap has been shown to cost tens of thousands of dollars in extra interest, in one real comparison, a homeowner who chose a HELOC over a cash-out refinance specifically to protect a 3.0% first mortgage saved over $50,000 across five years versus the refinance alternative.
If your current rate is already at or above today’s market rate, the calculation flips. A cash-out refinance can improve your terms on the whole loan while also getting you the cash, genuinely the better move in that specific situation. There’s no universal right answer here, it depends entirely on the gap between your rate and today’s rate.
How Each One Actually Works
A HELOC (home equity line of credit) is a revolving line secured by your home, sitting as a second lien behind your existing first mortgage, which stays exactly as it is. During the draw period, you can borrow, repay, and borrow again up to your approved limit, paying interest only on what you’ve actually drawn, similar in structure to a credit card but backed by your house. Rates are typically variable, and payments change as the balance and rate move. A close cousin, the home equity loan, works similarly but as a fixed-rate lump sum instead of a revolving line, worth asking about if you want a HELOC’s preserved-first-mortgage advantage with a fixed-rate cash-out refinance’s payment predictability.
A cash-out refinance pays off your existing mortgage entirely and replaces it with a new, larger one. The difference between the new loan and your old balance gets paid to you in cash at closing. You walk away with a single mortgage, a new rate, and a new term, not two separate loans to track.
What You’ll Actually Qualify For
Requirements differ more than people expect, especially once an investment property enters the picture. HELOC lenders commonly want a credit score of 640+ for an owner-occupied primary residence, but that bar rises to roughly 680+ when the HELOC itself is secured by an investment property, a second home, or sits in third-lien position, and 760+ for loan amounts above $400,000. A score of 740+ is typically what unlocks the best combined loan-to-value ratios, up to 85% in many programs. Cash-out refinances are generally more accessible on credit alone, commonly 620+ as a minimum, though meaningfully better rates show up at 700+. Both products typically want 20-25% equity retained after the transaction and a debt-to-income ratio under roughly 50%, though specific lender overlays vary.
The Real Risk Nobody Puts on the Label
Here’s the part worth keeping in mind before either option: both a HELOC and a cash-out refinance on your primary residence use that house, the one you live in, as collateral for money you’re about to bet on a completely different property. If the rental doesn’t perform the way you expected, the foreclosure risk doesn’t stay contained to the investment, it reaches the home you actually live in. That’s a categorically different risk profile than financing the new property on its own merits, and it’s worth being honest with yourself about before tapping either option, not after.
The Third Option: Leave Your Primary Home Out of It Entirely
If you already own a rental property, there’s a path that sidesteps the risk above completely: a DSCR cash-out refinance on the rental itself, not your primary home. It works the same way conceptually, refinancing the existing loan on that property for more than you owe and pocketing the difference, but it qualifies based on the rental’s own income, the same math covered in the DSCR loan guide and run directly through the DSCR loan calculator, not your personal income or your primary home’s equity. Your first house never enters the picture at all. This is usually the better option specifically for someone using rental equity to fund the next acquisition, rather than someone tapping a primary residence for their very first one.
What Happens to the Tax Deduction
This is genuinely more nuanced than most comparisons let on, and it’s worth getting exactly right rather than assuming either “yes, always deductible” or “no, never deductible.”
The home mortgage interest deduction (the one you’d claim by itemizing on Schedule A) only covers interest on debt used to buy, build, or substantially improve the specific home that secures the loan, this is the IRS Publication 936 framework. Use a HELOC secured by your primary residence to fund a down payment on a rental property, and that interest does not qualify under this framework, the money didn’t improve the home that’s backing the loan.
But that’s not the end of the story, and this is the piece that trips up a lot of otherwise-careful research. A completely separate set of rules, the interest tracing rules under Treasury regulations and IRS Publication 535, look at what the borrowed money was actually used for, regardless of what property secures the loan. Money borrowed against your primary residence but genuinely traced to purchasing a rental property can generally be deducted as a rental business expense on Schedule E instead, which doesn’t require itemizing at all and isn’t limited by the $750,000 acquisition-debt cap that governs the Schedule A deduction. In effect, the interest doesn’t lose its deductibility, it just moves to a different form, one that’s arguably better for a landlord.
The catch is entirely about documentation. The IRS wants to see the actual money trail, not receipts for what you eventually bought. Route the funds into a dedicated account and wire directly from there to the closing, and the trace is clean. Let the money sit in an account you also use for other spending, and untangling which dollars paid for what can turn into a real, expensive mess, one real example involved a $120,000 HELOC used for both a rental renovation and personal expenses in the same commingled account, costing over $1,400 in professional fees just to reconstruct which dollars went where. Decide the tax treatment you want before the first draw, not after.
One more thing worth flagging honestly: this entire framework stems from 2017 tax law that’s set to sunset after 2025 unless Congress acts, and as of this writing, no extension has been finalized. If it does sunset, the older, more permissive rules would return. Worth confirming current status with a tax professional before leaning too heavily on any of this in your planning, tax law is exactly the kind of thing that’s worth verifying fresh rather than trusting a snapshot from whenever an article was written.
Putting It Together
Start with your current mortgage rate against today’s rates, that single comparison rules out one option before you’ve looked at anything else. From there, weigh the real risk of putting your primary residence behind a bet on a separate property against a DSCR cash-out refinance on a rental you already own, which avoids that risk entirely if it’s available to you. And treat the tax question as a documentation problem to solve upfront, not an assumption to make after the money’s already spent.
Frequently Asked Questions
It depends most heavily on your current mortgage rate. If it’s below today’s market rate, a HELOC preserves that rate on your existing balance while a cash-out refinance would force you to give it up on the entire loan. If your current rate is at or above today’s rates, a cash-out refinance can improve your terms while also getting you the cash.
Roughly 680+ is common when the funds are earmarked for an investment property, higher than the 640+ threshold typical for a standard owner-occupied HELOC. Scores of 740+ generally unlock the best combined loan-to-value ratios, and loan amounts above $400,000 often require 760+.
Both a HELOC and a cash-out refinance use your primary residence as collateral for money spent on a separate property. If the rental doesn’t perform as expected, the foreclosure risk reaches the home you actually live in, not just the investment, a materially different risk than financing the new property on its own.
Yes, if you already own a rental. A DSCR cash-out refinance on that property qualifies based on its own rental income rather than your personal finances or your primary home’s equity, leaving your primary residence completely out of the transaction.
Not as the standard home mortgage interest deduction, since that only covers debt used to improve the home securing the loan. But under separate interest tracing rules, that same interest can generally be deducted as a rental business expense on Schedule E instead, provided the funds are clearly documented and not commingled with other spending.
Strongly recommended. The IRS interest tracing rules require demonstrating which specific dollars paid for the rental purchase, not just proving you eventually bought it. Routing the funds through a dedicated account and wiring directly to closing keeps that trail clean; mixing the money with personal spending can turn a simple deduction into an expensive documentation problem.
Yes. The current framework stems from 2017 tax legislation set to sunset after 2025 unless extended, and as of this writing no extension has been finalized. Confirm current rules with a tax professional before relying heavily on this in your planning.
A HELOC is a revolving line you can draw from repeatedly up to a limit, typically with a variable rate. A home equity loan is a fixed-rate lump sum instead, worth asking about if you want a HELOC’s preserved first-mortgage advantage combined with more predictable payments.
Sources: https://www.bankrate.com/home-equity/home-equity-loan-heloc-or-cash-out-refi/ · https://www.altgage.com/blog/heloc-vs-cash-out-refinance · https://www.lendmire.com/cash-out-refinance-vs-heloc-which-is-better-for-accessing-home-equity/ · https://www.refiguide.org/heloc-on-investment-property/ · https://taxstra.com/heloc-investment-property/ · https://honestcasa.com/blog/heloc-tax-deduction-rules-2026 · https://clearvaluelending.com/answers/heloc-tax-deduction-rules