How home loan portability works
Home loan portability, which lenders also call substitution of security or a security swap, lets you keep your existing loan, rate and features when you sell one property and buy another: the new property replaces the old one as the security. It avoids break costs on a fixed rate and the discharge and setup fees of a new loan, and it comes with rules about value, timing and what cannot be ported. This guide covers how it works, the two settlement paths, the exclusions, and what the lenders publish.
- Same loan, same lender, same rate; only the property securing it changes. Break fees do not apply on a fixed rate (St.George, ANZ)
- Like-for-like: the new property must be of equal or greater value, and a valuation may be required (Westpac)
- Two paths: simultaneous settlement, or deferred settlement with the sale proceeds held in a term deposit for up to 6 months (3 if you paid LMI) at St.George
- The limit cannot be increased inside the substitution; borrow more as a separate top-up (Macquarie, Westpac)
- No portability fee at St.George, but discharge, valuation and transfer fees; Macquarie says allow up to 28 days
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 based on a secured loan of $30,000 over 5 years for vehicle finance and $50,000 over 5 years for equipment finance, as required under the National Credit Code.
What is home loan portability?
ANZ's definition: a security swap, also known as substitution of security or loan portability, is when you keep your original home loan and swap the property being used as security for the loan from your old home to your new one. Macquarie describes it as changing the security property that secures your home loan, usually when you buy and sell at the same time. The loan account, balance, limit, rate, term and features all continue; the mortgage is discharged from the old title and registered on the new one. It is a variation of your existing loan, not a new loan, which is why the fees are smaller and the fixed rate survives.
When does portability pay?
Three situations. You are on a fixed rate. St.George publishes that by only substituting the property held as security, break fees will not be applicable when you sell and purchase during a fixed term, and ANZ publishes that a swap could help you avoid break fees and keep the same fixed rate. Your current loan is competitive. Discharging it to set up an identical loan elsewhere costs fees for no gain; St.George publishes that portability saves money on exit and new loan application fees. You want a simple settlement. The loan is already approved and the lender already knows you, so the credit work is the new property's valuation and a review of your position rather than a fresh application.
Portability does not pay when a refinance would get you a materially better rate anyway. Porting now and refinancing in six months means paying the substitution costs and then the switching costs; a refinance timed to the purchase pays once.
How does it work: simultaneous or deferred settlement?
Simultaneous settlement is the simple case: the sale and the purchase settle on the same day, the mortgage is released from one title and registered on the other, and the loan carries on. St.George publishes it as the path when you have a property ready to go and same-day settlement is an option.
Deferred settlement covers selling before you have bought. St.George publishes that the bank sets up a term deposit using the proceeds of the sale as security against the loan for up to six months (conditions apply), or up to three months if you pay lenders mortgage insurance on the current loan; you keep making repayments, you cannot withdraw the funds, and when the new property is ready to settle the term deposit is closed and the new property is secured against the loan. ANZ publishes the mirror image as a limitation: a longer settlement will not work if you cannot arrange a simultaneous settlement and your sale proceeds cannot be held as security in a term deposit. Buying before you sell is the other order, and that is a bridging loan, which St.George calls a relocation loan; it is a different product.
The rules: value, limit and property type
Westpac publishes the general rule as like-for-like substitution: the property being held as security is switched for a property of equal or greater value, and a valuation may be required for the new property. The loan limit does not move: Macquarie publishes that the facility limit cannot be increased as part of a substitution request, and Westpac publishes that loans where a limit increase is pending must complete it first. If the new home costs more, the extra is a separate top-up, assessed on your income; St.George publishes that you can apply to top up alongside portability. If the new home costs less, you may be asked to reduce the balance so the LVR still fits. ANZ publishes that your LVR is used to determine whether you are eligible for a swap at all.
What cannot be ported?
Westpac publishes the fullest exclusion list: using commercial security as the substitute; loans taken out by non-residents; Sustainable Upgrades home and investment loans; home loans under the Australian Government 5% Deposit Scheme; loans with a delinquency history; and loans where a settlement or limit increase is pending. St.George excludes commercial substitutions, non-resident loans and loans with a delinquency history. Macquarie publishes that substitution is typically not available on one of its loan series and to contact it to discuss options. Vacant land, unusual properties and properties outside the lender's security policy are the other common refusals.
What do lenders publish on portability?
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 | Value rule | Deferred settlement | Borrowing more | Exclusions | Fees and timing |
|---|---|---|---|---|---|
| Westpac | Like-for-like: equal or greater value; valuation may be required | Simultaneous or deferred settlement offered | A pending limit increase must be completed first | Commercial security; non-residents; Sustainable Upgrades loans; 5% Deposit Scheme loans; delinquency history; pending settlement or increase | Not published; apply via the Property and Security Request Form before selling |
| St.George | Not published as a rule; LVR and credit criteria apply | Term deposit on the sale proceeds for up to 6 months, 3 months if LMI was paid; funds locked, repayments continue | Can apply to top up alongside portability | Commercial substitution; non-resident loans; delinquency history | No portability fee; discharge, valuation or transfer fees may apply |
| ANZ | LVR determines eligibility; valuation of the new property | Not possible if sale proceeds cannot be held in a term deposit | Upsizing named as a reason to increase the loan | Not published | Response time 1 to 3 days; keeps the fixed rate, avoids break costs |
| Macquarie | Subject to credit assessment and approval | Not published | Limit cannot be increased within the substitution; separate increase | Typically not available on one loan series (BSB 183) | Allow up to 28 days; request by email with existing and new property details |
| CommBank | Publishes a substitution of security guide (PDF) rather than a product page; terms not restated here | ||||
What does it cost, and how long does it take?
St.George publishes that a portability fee is not charged, but you may have to pay a discharge fee for the existing mortgage and valuation or transfer fees, and that any applicable fees are far outweighed by the costs of refinancing a new home loan. The land registry charges to discharge the mortgage from one title and register it on the other, and the new property is valued. On timing, Macquarie publishes that you should allow up to 28 days for the substitution to be fully completed and to make contact as soon as possible; Westpac and St.George both say to apply before you sell and to talk to a home lender first to confirm eligibility. A broker lines the substitution up with your sale and purchase dates and lodges any top-up as a parallel application, and Your Finance Guide refers you to one licensed broker partner for that; we do not lend or assess applications ourselves.
Moving-house guides
Portability, bridging, and what a full switch costs.
Home loan portability FAQs
Is porting a mortgage a good idea?
What are the rules for porting a mortgage?
Is it good to transfer a home loan from one bank to another?
Can I port a fixed-rate loan?
Can I port my loan and borrow more?
What if I sell before I have bought?
What does portability cost?
How long does portability take?
Take your loan with you
Tell us your settlement dates and whether you are on a fixed rate, and we refer you to one licensed broker partner who checks portability against a refinance on total cost and lines up the substitution with your sale and purchase. Free for borrowers, no obligation.