Second Mortgage vs HELOC:Fixed Rate or Revolving Credit?
A second mortgage locks in one lump sum at a fixed rate. A HELOC gives you a revolving line you can draw, repay, and reuse. Both put your home equity to work — here's how to choose the right one for your goals.
Saman Khanian
Author & Mortgage Professional
Head-to-Head
Fixed vs revolving
Put your equity to work
The Difference in One Sentence
A second mortgage is a fixed-rate lump sum repaid on a set schedule. A HELOC is a revolving line of credit you draw from as needed — like a credit card secured by your home.
Fixed Lump Sum
Second Mortgage
A second mortgage (a home equity loan) gives you a single lump sum at closing, repaid in equal monthly installments at a fixed rate.
- Fixed rate for the full term
- One lump sum at closing
- Predictable, equal monthly payments
- Ideal for a known, one-time expense
Revolving Credit
HELOC
A Home Equity Line of Credit gives you a pool of money you can borrow from, repay, and reuse during the draw period.
- Variable rate (often starting lower)
- Draw funds as needed during draw period
- Pay interest only on what you use
- Great for ongoing or uncertain costs
Second Mortgage vs HELOC: Side-by-Side
The fastest way to decide is to compare the features that matter most to your situation.
| Feature | Second Mortgage | HELOC |
|---|---|---|
| How You Receive Funds | Single lump sum at closing | Draw as needed during draw period |
| Interest Rate | Usually fixed | Usually variable |
| Monthly Payment | Fixed & predictable | Varies with balance & rate |
| Repayment Structure | Fixed term (e.g. 5–30 yrs) | Draw period, then repayment |
| Best For | One-time, known expenses | Ongoing / uncertain expenses |
| Rate Risk | None (rate is locked) | Higher (rates can rise) |
| Closing Costs | Typically similar to a mortgage | Often lower or waived |
| Flexibility | Low — fixed amount | High — reuse as you repay |
Rule of thumb: Choose a second mortgage when you want a fixed, predictable payment for a one-time cost like debt consolidation or a major project. Choose a HELOC when you want flexibility and don't know the exact total — like staged renovations.
What Is a Second Mortgage?
A second mortgage is a loan secured by your home in addition to your first mortgage. The most common form is a home equity loan — you receive one lump sum at closing and repay it over a fixed term at a fixed interest rate.
- Fixed interest rate for the full term
- Predictable, unchanging monthly payment
- Terms often range from 5 to 30 years
Because the rate and term are locked, your monthly payment never changes — which makes a second mortgage easy to budget around and a strong fit for consolidating a known balance.
What Is a HELOC?
A HELOC (Home Equity Line of Credit) is a revolving credit line secured by your home. During the draw period you can borrow up to your limit, repay, and borrow again — much like a credit card.
- Rates are commonly variable, tied to the prime rate
- You control when and how much you borrow
- Interest-only payments are often available during draws
A HELOC's rate is typically variable and tied to the prime rate, so your payment can move with the market. That variability keeps the starting rate attractive — and is the main trade-off to weigh.
Which Is Better for You?
Neither option is universally "better" — the right choice depends on your goals, timeline, and comfort with rate risk.
Choose a Second Mortgage if…
- You have a one-time expense with a known amount
- You want a fixed payment you can budget around
- You're consolidating debt and want to pay it off on a schedule
- You want protection from rising interest rates
- Discipline matters more to you than flexibility
Choose a HELOC if…
- You want flexibility to draw funds over time
- Your project — like a staged renovation — has unknown costs
- You plan to pay it down quickly and reuse it
- You want the lowest possible starting rate
- You're comfortable with a variable rate
The best equity option is the one that fits your plan.
Fixed Rate or Revolving — What About Rates?
A second mortgage's fixed rate means you lock in your cost today and your payment never moves. A HELOC's variable rate can start lower but rise if the market shifts. In a changing rate environment, many homeowners choose to lock in — while others prefer the flexibility and lower starting cost of a line of credit.
Pro tip: Ask about rate caps on a HELOC (how high your rate can climb) and any conversion feature that lets you lock a portion of your balance into a fixed rate.
Frequently Asked Questions
Common questions homeowners ask when comparing a second mortgage and a HELOC.
Is a second mortgage the same thing as a HELOC?
Which has a fixed rate — a second mortgage or a HELOC?
Which is cheaper, a second mortgage or a HELOC?
Can I get a second mortgage or HELOC if I already have a first mortgage?
Which is better for debt consolidation?
Do I need to pay off my first mortgage to get one?
Saman Khanian
Saman Khanian is a mortgage professional and the CEO of Equitable Lending, where he helps homeowners and investors find financing solutions that fit their goals. He writes about home equity products, Non-QM lending, refinancing strategies, and mortgage planning for homeowners and entrepreneurs.
Disclosure: This article is for informational purposes only and does not constitute a loan commitment, rate quote, or financial advice. Second mortgage and HELOC guidelines, rates, fees, and eligibility vary by lender, borrower, property, and state. All loans are subject to credit approval and underwriting. Equitable Lending is a licensed mortgage lender — see our Licensing Information page. Contact a licensed loan officer to discuss your specific scenario.
Fixed Rate or Revolving — Let's Find Your Fit
Our specialists will compare a fixed-rate second mortgage and a HELOC against your goals and recommend the strongest option. Start your application today.
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