Split home loans: part fixed, part variable
A split home loan divides one mortgage into separate accounts, usually one fixed and one variable, so part of the loan has a locked rate and part keeps unlimited extra repayments, offset and redraw. The blended rate sits between the two: in NAB's example, $300,000 fixed for three years plus $200,000 variable is about $3,063 a month, and NAB caps extra repayments on the fixed part at $20,000 per fixed period. It suits borrowers who want certainty on part of the loan but still plan to pay extra or use an offset, and BankSA allows up to four splits on one property.
- One loan, separate accounts: a fixed split for certainty and a variable split for extra repayments, offset and redraw (Westpac’s definition)
- NAB’s example: $300,000 fixed at 6.00% for three years plus $200,000 variable at 6.50% is about $3,063 a month combined
- Extra money goes to the variable split; the fixed split is capped (NAB $20,000 per fixed period; St.George and BankSA $30,000) and break costs apply above it
- Ratio: no perfect formula (NAB); make the variable split at least as big as the extra money you expect to put in over the fixed term
- You can split at any time (CommBank), into two variable loans as well (Westpac), and up to four accounts at BankSA
WARNING: This comparison rate is true only for the example given and may not include all fees and charges. Different terms, fees, or other loan amounts might result in a different comparison rate. Comparison rates are calculated on a secured loan of $150,000 over 25 years for home loans, a loan of $30,000 over 5 years for car and personal loans, and $50,000 over 5 years for equipment finance, unless the lender states another basis.
What is a split home loan?
Westpac's definition: a split home loan divides your loan balance into separate accounts, so you can enjoy the security of a fixed rate loan alongside the flexibility of a variable rate loan. CommBank adds that you nominate a portion to have a fixed rate and the remainder a variable rate, and that the proportion is entirely up to you. Each split has its own rate, its own repayment and its own rules; the property secures all of them and you are liable for all of them. Westpac publishes that a split can also be two variable loans, which is how investors separate owner-occupier and investment borrowing.
Worked example: NAB's $500,000 split
| Split | Amount | Rate in the example | Features | Extra repayments |
|---|---|---|---|---|
| Fixed, three years | $300,000 | 6.00% p.a. | Certainty of repayment for three years | Up to $20,000 in the fixed period without economic costs (NAB) |
| Variable | $200,000 | 6.50% p.a. | Offset accounts and redraw | Unlimited |
| Combined | $500,000 | Blended about 6.20% p.a. | — | About $3,063 a month total (NAB) |
The blended rate is nothing special; it is the weighted average of the two. What the borrower has bought is a $300,000 anchor that cannot rise for three years and a $200,000 account that takes every spare dollar and the offset balance without a break cost. NAB's rates are its published example, not a current offer.
How do you choose the split ratio?
NAB publishes that there is no perfect formula and offers three starting points: first home buyers may choose a 50/50 split to balance certainty with flexibility, families managing school fees or renovations might lean more towards fixed for stability, and investors weigh the tax side. Westpac and BankSA publish calculators that slide the ratio and show the two repayments. The practical test is the variable split's size: add up the extra repayments you expect to make over the fixed term and the savings you will hold in offset, and make the variable split at least that large. If it is smaller, the surplus has nowhere to go but the fixed split, where NAB caps it at $20,000 per fixed period and St.George and BankSA at $30,000, and a break cost applies above that.
What do lenders publish on split loans?
Checked against each lender's published page on 20 September 2026; "Not published" means the page does not state it. Policies change without notice, so confirm before relying on them.
| Lender | Number of splits | Fixed terms | Extra repayments on the fixed split | When you can split | Other published terms |
|---|---|---|---|---|---|
| CommBank | Multiple parts; number not stated | One to five years | Penalties for breaking a fixed term | Any time, from settlement or through the life of the loan; switch or refix online for eligible loans, interest-only loans by phone | Ratio entirely up to you |
| NAB | Not stated | Three years in its example | Up to $20,000 per fixed period without economic costs | Restructure path for existing customers | $500,000 example: $300,000 fixed at 6.00%, $200,000 variable at 6.50%, about $3,063 a month; ratio guidance for first home buyers, families and investors |
| Westpac | Fixed plus variable, or two variable loans | One to five years | Break costs may apply if paid ahead or switched early; no cap on the variable split | Not stated | Publishes a split loan calculator; two variable splits to separate owner-occupier and investment portions or use different features |
| ANZ | Not stated | Fixed rates shown with LVR-based discounts at 80% or less | Early repayment costs can be very large and change daily; check first | Not stated | $10 a month per offset account on the variable split; comparison rate on $150,000 over 25 years |
| BankSA | Up to four separate fixed and variable accounts against the same property | Fixed and variable, P&I or interest-only | $30,000 prepayment threshold for the entire fixed period | Apply online for conditional approval or a new split | Publishes a split calculator |
Extra repayments, offset and break costs on each split
The rule that makes a split work: everything extra goes to the variable split. Offset accounts attach to it (ANZ publishes $10 a month per offset account), redraw comes from it, and it has no cap on extra repayments at any of the lenders above. The fixed split takes its scheduled repayment and, if you want, up to the lender's cap, and the break costs guide explains what happens above it and when you sell or refinance during the fixed term. If you want to hold the fixed split's rate between application and settlement, the rate lock guide covers the fees; Bank Australia charges its rate lock per fixed split, Easy Street once per property.
When the fixed split ends, and when a split is the wrong answer
At the end of the fixed term that split reverts to the lender's variable rate, which may be higher than the rate on your existing variable split; the fixed rate ending guide covers refixing, merging or refinancing in the 90 days before. A split is the wrong structure if you will never use the variable features (fix the lot), if you plan to repay most of the loan early or sell within the fixed term (keep it variable), or if the two rates are so far apart that the certainty costs more than it is worth. A broker models the ratio and the total cost across lenders in one pass; get matched with a licensed broker who works this kind of lending and they contact you.
Fixed and variable guides
The two halves of a split, and what happens at the edges.
Split home loan FAQs
Is it better to split a home loan?
Can you split a home loan between two people?
Is it worth splitting your mortgage?
What ratio should I split?
Can I make extra repayments on a split loan?
How many splits can I have?
Can I split my existing loan?
What happens when the fixed split ends?
Get the split right the first time
Tell us your loan size, how much you expect to pay extra, and whether any of it is investment borrowing, and we refer you to one licensed broker partner who structures the splits and compares the total cost across lenders. Free for borrowers, no obligation.