What is the difference between a HELOC and a second charge mortgage?
The comparison is between a revolving facility and a lump-sum loan. A HELOC lets you draw funds up to a limit, repay, and where the agreement allows, draw again. A second charge mortgage in this comparison pays out one lump sum. Both are ways of borrowing against a home, and either can sit alongside an existing mortgage. They are not mutually exclusive charge categories.
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ImportantAs a mortgage is secured against your home, your home could be repossessed if you do not keep up the mortgage repayments. Think carefully before securing other debts against your home.
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A revolving facility and a lump-sum loan are different ways of releasing money. A revolving facility can itself be secured by a charge on the home, including behind an existing mortgage. This page does not treat "HELOC" and "second charge" as two charge ranks that cannot overlap.
How does a HELOC work?
A HELOC, short for home equity line of credit, is a revolving facility secured on a home. You may draw funds, repay them and, where the agreement permits, draw again up to a limit. That revolving structure is the point of this comparison. It is not a separate charge category from a lump-sum loan, and UK availability varies by provider.
For the full explanation, including a glossary and cost factors, see the HELOC guide.
How does a second charge mortgage work?
In this comparison, a second charge mortgage means a lump-sum loan secured on a home, usually ranking behind an existing first mortgage. It pays out once, with its own repayment schedule. The first mortgage usually stays in place. Charge rank describes the security. It is separate from whether a different product lets you draw funds more than once.
The existing first mortgage stays in place, but total secured debt on the property increases. Read more at second charge mortgages.
How do the costs and repayments differ?
HELOC-style facilities commonly have variable pricing, but the reference rate, margin, payment rules and availability are provider-specific. A headline rate alone does not show the total cost or how payments might change. Compare the agreement, fees, repayment structure and rate-change terms for any product under consideration.
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A headline rate alone rarely tells the full story. The APRC and total amount repayable give a fuller picture for either structure.
What risks do both products share?
Both structures are secured on a home, so missing repayments can lead to arrears and, ultimately, repossession. Variable pricing can raise payments where it applies, and a longer term or additional secured debt can raise total cost. Each structure also carries a distinct risk tied to its own mechanics.
ImportantAs a mortgage is secured against your home, your home could be repossessed if you do not keep up the mortgage repayments. Think carefully before securing other debts against your home.
Shared risks include repossession, affordability pressure and the effect of rate changes where a product is variable. Distinct risks include, for a HELOC-style facility, a revolving balance that can persist or grow, and the change in terms when a draw period ends; for a second charge mortgage, committing to the full lump sum and its schedule from the outset.
When does the product structure matter most?
The structural difference tends to matter most where borrowing needs are staged rather than a single known amount, where payment certainty is a priority, or where an existing mortgage deal makes some alternatives less attractive. These are questions to discuss with a lender or Loans Warehouse, not conclusions this page can reach.
Neutral questions worth discussing:
- Is the amount needed known now, or likely to be needed in stages over time?
- Is a fixed repayment schedule important, or is flexibility more valuable?
- Does the existing mortgage deal affect how attractive a remortgage would be?
See how it works for what happens after an enquiry starts.
Questions to compare before an enquiry
- The total amount that might be needed, now or over time.
- Whether redrawing matters, or a single lump sum is sufficient.
- How much payment certainty is wanted.
- What fees and exit terms apply.
- The purpose of the borrowing and any likely change in income.
- The risks specific to each structure, covered above.
Start an enquiry to discuss these points with Loans Warehouse.
Frequently asked questions
Is a HELOC the same as a second mortgage?
No. The useful difference is how the money is released, not which charge rank the product sits in. A HELOC is a revolving facility: you can draw, repay and, where the agreement allows, draw again up to a limit. A second charge mortgage, in this comparison, is a lump-sum loan. Either can be secured on a home that already has a mortgage. They are not two charge types that exclude each other.
Which has a fixed repayment?
A second charge mortgage more commonly offers a fixed repayment schedule, though fixed or variable rate options depend on the specific product. A HELOC-style facility more often has payments that vary with the amount drawn and the current rate. Checking a specific product's terms is the only way to confirm its actual structure.
Can a HELOC be redrawn?
Where a HELOC-style facility permits it, funds repaid during the draw period may be drawn again up to the agreed limit. This feature depends entirely on the individual agreement, and not every revolving product allows unlimited redrawing. A second charge mortgage does not normally offer this feature once the lump sum is paid.
Does either product affect the first mortgage?
A lump-sum second charge mortgage is a separate loan and usually leaves the first mortgage in place. A revolving facility can also be secured without replacing that mortgage, where a provider offers it that way. The charge rank depends on the agreement. Total secured borrowing can increase either way, and repayments still have to be met. Neither of these is a remortgage.
Can both put a home at risk?
Yes. Both a HELOC-style facility and a second charge mortgage are secured on the home, so missing repayments on either, or on the existing first mortgage, can lead to arrears and ultimately repossession. This risk applies regardless of which structure is used, and is not unique to either product.