How Much a HELOC Costs Monthly vs Replacing a Low First Mortgage

The Quick Read: A HELOC adds a second monthly payment that is mostly interest at first, floats with the market, and steps up when the draw period ends, while replacing the first mortgage gives you one new payment that reprices your entire balance, including the cheap part. The right pick depends on how the loan is structured, not on one dollar figure. Pricing lives in the calculator, so this article compares how each option behaves.

• A HELOC leaves your first mortgage alone and adds a second payment on top of it.
• A cash-out refinance replaces the first mortgage with one new, larger loan.
• On an investment property, the network HELOC qualifies you personally and cannot be held in an LLC.
• A DSCR cash-out qualifies primarily on property-level rental income covering the payment, subject to lender guidelines.
• Your old first mortgage balance and terms decide more of this choice than anything else.

The Honest Answer First

A HELOC fits an investor who owns the rental in their own name, has strong personal credit, and wants to keep a cheap first mortgage untouched. A cash-out refinance fits an investor who holds title in an LLC, wants more leverage headroom, or wants to move the whole loan onto a fixed structure.

Neither one is better in general. A HELOC protects what you already have. A cash-out gives you one clean loan and a wider set of ways to qualify.

One note on scope. Lendmire is a broker that arranges financing through select wholesale lenders. The investment-property HELOC discussed here is available in 16 full-service states only. The DSCR side is a non-QM investor platform covering 40 states and Washington, D.C. Every figure below is subject to lender guidelines and full file review, and none of it is a commitment to lend.

Side-by-Side

Both columns below describe Lendmire’s wholesale network guidelines for an investment property. Where the table says a figure varies, it varies by lender, leverage, and loan size.

*Subject to lender program eligibility.

Three terms in that table need plain definitions. CLTV is combined loan-to-value: your first mortgage plus the new line, divided by the property’s value. DTI is debt-to-income, meaning your monthly debts measured against your personal income. PITIA is principal, interest, taxes, insurance, and any association dues, the full monthly obligation a DSCR lender measures rent against.

Why the Monthly Picture Looks Different

With a HELOC, you make two payments: the one on your existing first mortgage and the one on the line. With a cash-out, you make one.

The HELOC prices only the new money. Your old loan keeps its balance, its schedule, and its cost. A cash-out puts new terms on everything, so the cheap part of your debt gets repriced along with the cash you pull out.

That is the whole reason the low-first-mortgage question exists. If your first mortgage is cheap compared with today’s market, replacing it costs you something you cannot get back.

What Moves a HELOC Payment

A HELOC payment has two phases. During the draw period, many plans let you pay interest only, though some require a minimum that includes principal. Then repayment begins and principal joins the payment. The CFPB’s HELOC brochure lays out both phases and notes that the payment can climb when the draw ends.

On the network’s investment line, the draw runs five years and repayment runs 25 years. Pricing floats across both phases and does not convert to fixed. Some consumer HELOCs let you fix part of the balance. The investment line does not.

Three things move the payment:

• Balance drawn. At least 75% of the line is drawn at closing, so interest starts on most of the line right away. This is not idle dry powder.
• Market movement. The payment can change even if you borrow nothing more, because the pricing floats.
• The phase change. When the draw ends, principal joins the payment and the monthly obligation steps up. Interest-only payments also mean the balance does not shrink unless you pay extra.

Underwriting accounts for this. The lender reviews your file on the interest-only payment calculated on the maximum draw, with DTI capped at 50% (45% for credit profiles from 600 to 679). On an investment property, the credit floor is 700.

What Moves a Cash-Out Payment

A cash-out refinance is simpler to describe. One loan pays off the old first mortgage, hands you the extra cash at closing, and produces one payment. Most files in the network lean on the 30-year fixed structure. Extended terms, such as 40-year, and interest-only periods are available through select lenders. Some investors prefer an ARM structure, and those exist too.

The monthly cost depends on the size of the new balance and the structure you choose. It does not step up on a schedule the way a HELOC does. That predictability is the main thing you pay for.

Closing costs generally run higher on a cash-out because it is a new mortgage on the full balance. A HELOC carries its own up-front charges, so compare the full set of terms on both. Tax treatment can depend on how the funds are used and how the property is held; investors should keep clear records and speak with a qualified tax professional before relying on any deduction.

When a HELOC Is the Better Fit

A HELOC wins when the first mortgage is the asset worth protecting. Say your first mortgage is cheap and your equity is real. Replacing it means giving up that cheap debt on the entire balance just to reach a slice of equity. A HELOC borrows only against the slice.

It also fits these situations:

• You hold title personally or in a revocable living trust. Those are the only two vesting options. An LLC, corporation, partnership, or irrevocable, blind, or land trust cannot hold title.
• Your credit is strong. An investment line wants a 700 score or better. Most DSCR programs would accept less.
• Your cash need is moderate. Investment lines cap at $500,000 total, with no tier above that. Lines at or below that size ordinarily run on an automated valuation instead of a full appraisal.
• You can absorb a step-up. The payment rises when repayment begins. If your cash flow is already thin, plan for that.

Property type matters too. The HELOC covers single-family, 2-4 units, PUDs, townhomes, and condominiums, including non-warrantable ones. It does not cover manufactured homes, co-ops, condotels, log homes, commercial, mixed-use, or agricultural zoning.

Two limits catch investors off guard. A borrower is limited to three lines, and a borrower with more than 15 financed properties is not eligible. If you are scaling a portfolio, those caps matter.

When Replacing the First Mortgage Is the Better Fit

A cash-out wins when the property is the credential, not you. DSCR loans are designed for non-owner-occupied investment properties. Because they are business-purpose investor loans, they are reviewed differently from a standard owner-occupied mortgage. The lender asks whether rent covers PITIA, which is how DSCR gets calculated: monthly rent divided by that full obligation.

That shift opens doors a HELOC keeps closed:

• LLC ownership. A cash-out can often keep the property in your entity, subject to lender program eligibility. A property already deeded to an LLC needs a vesting change before the HELOC works.
• More leverage headroom. On a standard rental, cash-out tops out around 75% LTV across most of the network. On short-term-rental collateral, it tops out at 70%. The investment HELOC stops at 70% CLTV, so a cash-out can reach a bit further.
• Larger cash needs. Loans reach up to $3,000,000 on standard programs, with smaller balances available through select lenders. Above $2,500,000, the network generally holds to 30-year fixed structures.
• Wider credit range. A 620 floor exists in parts of the network. Most programs want around 660, and 700 or better opens the strongest leverage tiers.
• Predictability. One payment, one structure, no draw-period step-up.

Plan on seasoning, too. About six months of ownership is the common expectation for a cash-out. Coverage of 1.00 is where select programs start, and stronger ratios open better terms and leverage. A separate select-lender path goes below 1.00 with leverage and terms adjusted. No-ratio structures exist only through select lenders, generally for borrowers who already own a primary residence.

Reserves vary by lender, leverage, loan size, and transaction type. About six months of PITIA is common. Conservative rate-and-term files at modest leverage under $1,500,000 can see reserves waived, and larger loans typically step up to around nine months.

Clearing 1.00 coverage does not mean the property cash flows. Repairs, vacancy, management, utilities, and capital expenses sit outside the DSCR calculation. Property types differ here as well. DSCR is not offered on manufactured homes, log homes, or barndominiums. For the full picture of how these loans work, read the complete DSCR loans guide.

What a Broker Sees on These Files

A pattern shows up across wholesale files. Investors with a very cheap first mortgage and modest cash needs usually lean toward a HELOC on a home they live in or an investment line, if their vesting allows it. Investors with an LLC wrapper, several properties, or a bigger cash need usually end up at a cash-out, because the entity and leverage rules decide the question before the monthly cost does.

The order of moves matters, too. A recent cash-out followed by a HELOC application, or the reverse, can run into seasoning and combined-leverage checks. Sketch the sequence before you apply for either one. For a related look from the other direction, see Lendmire’s piece How Much a Rental HELOC Saves Over Replacing a Low First Mortgage.

Hidden Costs and the Home-Line Workaround

Some investors skip the investment line and draw on a HELOC secured by their primary residence. On this network, a primary-residence line can reach higher leverage, with a ceiling of 90% CLTV that exists only at a 720-or-better credit profile. Lines above $500,000 are primary-residence only, require a 700 score or better (720 on the longer-runway structure), cap at 75% CLTV, and need a full appraisal.

The tradeoff is risk. Your home secures the debt, so a rental problem becomes a home problem. Weigh that before you use a residence line to fund a rental.

Two quieter costs deserve a look as well. First, with a HELOC you carry two loans, which means two payments to track and two sets of terms to watch. Second, with a cash-out, the closing costs apply to the whole new balance, not just the cash you take out.

A Simple Way to Compare Your Own Numbers

You do not need a dollar figure to start. Ask these questions in order:

1. Can the property sit in an LLC, or must it? If it must, the HELOC is off the table unless you change the vesting.

2. How cheap is your current first mortgage? The cheaper it is, the more a cash-out costs you in lost value.

3. How much cash do you need? Over $500,000 on an investment property pushes you to a cash-out.

4. How long will you hold the loan? A long hold favors one predictable structure. A short hold favors the HELOC, because you may pay it off before repayment begins.

5. Can you handle a payment that moves? If not, the cash-out’s fixed spine is worth more to you.

Then run the HELOC side through the site’s illustrative calculator. It gives an estimate you can edit, not a quote.

The Balanced Verdict

Choose the HELOC when your first mortgage is the asset worth protecting, you hold title personally, your credit is strong, and your cash need is moderate. Choose the cash-out when the property or the entity should carry the loan, when you need more headroom or a bigger loan, or when payment certainty matters more than the old first mortgage.

Both options ask for equity. The strongest files clear two tests: enough equity and enough coverage or credit to support the new debt. A bigger equity cushion can lower the payment and lift DSCR, but it never erases leverage caps, credit floors, reserve rules, or property eligibility.

If you are considering a home equity line and want to see how the numbers work, Lendmire can help you compare HELOC options based on the property, the equity available, credit profile, combined leverage, and your goals. You can reach the team at 828-256-2183.

About Lendmire

As a mortgage broker (NMLS# 2371349), Lendmire helps homeowners and real estate investors in its 16 full-service states open home equity lines of credit arranged through wholesale lenders. Lendmire is never the lender; line amounts, ceilings and terms are set by the lender under its guidelines. Scotsman Guide named Lendmire a Top Mortgage Workplace in both 2025 and 2026.

References

1. CFPB, What You Should Know About HELOCs