---
title: "Your Bank Is Charging You Too Much Interest. Here's How to Fix It in One Phone Call."
description: "Australian banks charge loyal customers higher rates than new ones. The loan retention department hack, the 2-year refinance cycle, and why your broker might not have your best rate."
author: Yan Zhu
date: 2026-03-19
category: Finance & Tax
url: https://premiumrea.com.au/blog/mortgage-interest-rate-negotiation-australia
tags: ["mortgage", "interest rate", "refinancing", "bank negotiation", "loan retention", "Australia"]
---

# Your Bank Is Charging You Too Much Interest. Here's How to Fix It in One Phone Call.

*By Yan Zhu, Co-Founder & Chief Data Officer at PremiumRea — 2026-03-19*

> The longer you stay with your bank, the worse your interest rate gets. That is not cynicism. It is documented bank pricing strategy, and it costs the average Australian mortgage holder thousands of dollars every year.

I am going to teach you something that will save you between $2,000 and $8,000 per year. It takes one phone call. It requires zero paperwork. And your bank is praying you never find out about it.

In Australian banking, there is an unwritten rule so blatant it borders on insulting: the longer you stay with a bank, the higher your interest rate drifts relative to what new customers receive. Banks call this "back-book pricing." Consumer advocates call it loyalty tax. I call it a wealth transfer from the passive to the informed.

The major banks — CBA, ANZ, Westpac, NAB — regularly offer new-to-bank customers rates that are 30-60 basis points below what existing customers pay on equivalent products. On a $600,000 investment loan, 50 basis points is $3,000 per year. Over three years without refinancing, you have gifted your bank $9,000 in excess interest.

That is not pocket change. That is the deposit on your next investment property's stamp duty.

## The one phone call that saves thousands

Here is exactly what you do. Pick up the phone. Call your bank. When the automated system asks what you need, do not say "existing loan enquiry." Say: "I want to speak to the loan retention department."

Loan retention. Remember those two words.

This is the department whose sole job is to prevent you from leaving. They have authority to offer rate discounts, fee waivers, and cashback incentives that the regular customer service team cannot access.

When you get through, be direct. Do not apologise. Do not explain your life story. Say this:

"I have been reviewing my loan and I have received a competitive offer from [name another bank — ANZ, Bankwest, whoever]. Unless you can match or beat their rate, I will be refinancing. I need your best retention rate today."

That is it. No negotiation wizardry required. No MBA needed. Just the credible threat of departure.

In our experience helping clients manage their loan portfolios, this single phone call typically produces a rate reduction of 20-50 basis points. On a $600,000 loan, that is $1,200-$3,000 per year — achieved in a fifteen-minute conversation.

> "It is the same logic as bargaining at a market stall. You say 'give me a better price or I walk.' The bank's retention department exists because walking is exactly what they do not want you to do." — Yan Zhu, PremiumRea

## The two-year refinance cycle

The retention call is a short-term fix. For a structural solution, you need a refinancing rhythm.

We advise our clients to reassess their loan every 18-24 months. Not necessarily to refinance — sometimes the retention offer is sufficient — but to benchmark. The Australian mortgage market is intensely competitive, with banks offering cashback incentives of $2,000-$4,000 to attract refinancers.

Here is how the cycle works in practice:

**Month 1-18**: You are on your current loan. Interest rate is competitive because you negotiated at origination.

**Month 18**: Call the retention department. Secure a rate reduction. If the reduction is meaningful (20+ basis points), stay for another 12 months.

**Month 24-30**: If the retention offer was inadequate, or if competitor cashback offers have increased, initiate a formal refinance. Our broker partners — we work with vice-president-level bankers at the Big Four, not junior brokers — can typically process a refinance in 2-3 weeks.

The cashback alone often covers the legal and discharge fees. Net result: a lower rate, a few thousand dollars in cash, and a reset of the loyalty-tax clock.

Over a decade-long investment holding period, this cycling saves $20,000-$40,000 in interest costs. That is a granny flat's worth of savings, simply from refusing to be a passive borrower.

One important distinction: we strongly recommend working with a senior banker at one of the Big Four rather than a mortgage broker for investment loans. Brokers receive a trailing commission of approximately 0.15% from the lender — a cost ultimately borne by you through marginally higher rates. A senior banker has more discretion on pricing, faster approval authority, and can sometimes approve loans that broker-channel applications would reject.

Our network includes vice-president-level contacts at ANZ, CBA, and Bankwest. These are not junior lenders reading from a script. They have genuine authority to approve exceptions, waive fees, and secure rates that the broker channel cannot access.

## Interest-only versus principal-and-interest: the investment tax equation

While we are talking about loan structure, let me address the single most common mistake I see in investment loan setup.

The majority of investment property owners in Australia are on principal-and-interest (P&I) loans. This is almost always wrong for investment properties.

Here is why. On an investment loan, the interest component is 100% tax deductible. The principal repayment component is not deductible at all. By choosing P&I, you are voluntarily reducing your tax deduction by paying down non-deductible principal.

The smarter structure: interest-only (IO) on investment loans, and direct any surplus cash into the offset account attached to your owner-occupied loan (where the interest is not tax deductible).

The rate differential between IO and P&I is typically 10-30 basis points. On a $600,000 loan, that is $600-$1,800 per year in additional interest cost. But the tax benefit of maintaining maximum deductible interest easily exceeds this differential for anyone in the 37% or 45% marginal tax brackets.

At a 37% marginal rate, every $10,000 in investment loan interest generates $3,700 in tax savings. At 45%, it generates $4,500. Those savings compound year after year, whereas the P&I approach slowly erodes your deduction base while building equity in the wrong asset (your investment property instead of your home).

> "The only debt you should be paying down is the one attached to your home — because that interest is not deductible. Investment loan interest is a tax asset. Preserve it." — Yan Zhu, PremiumRea

## Frequently asked questions

**Will calling the retention department hurt my credit score?**
No. Calling your existing bank does not generate a credit enquiry. Only formal loan applications to new lenders create hard enquiries on your credit file. The retention conversation is internal to your existing bank.

**How often can I refinance without it looking bad?**
Every 18-24 months is standard and will not raise red flags. Multiple refinances within 12 months may make lenders cautious, as it suggests you are churning for cashback rather than genuinely managing your finances.

**Is it worth refinancing for less than 30 basis points?**
Probably not, once you factor in discharge fees ($300-$400) and the time involved. The sweet spot is 40+ basis points or a cashback offer exceeding $3,000. Below that threshold, call retention instead.

**Can self-employed borrowers use this strategy?**
Absolutely. Self-employed borrowers (ABN holders with 18+ months of trading history and GST registration) often pay higher rates by default. The retention call is even more valuable, as the alternative — a full refinance with new documentation requirements — is more burdensome for self-employed applicants.

## References

1. [ASIC Moneysmart, 'How to negotiate a better home loan deal', updated March 2025.](https://moneysmart.gov.au/home-loans/switching-home-loans)
2. [Reserve Bank of Australia, 'Mortgage Rate Statistics — Owner-Occupier and Investor Rates', August 2025.](https://www.rba.gov.au/statistics/tables/)
3. [Australian Competition and Consumer Commission (ACCC), 'Home Loan Price Inquiry — Loyalty Tax Findings', 2024.](https://www.accc.gov.au/)
4. [Canstar, 'Investment Home Loan Rate Comparison — IO vs P&I', September 2025.](https://www.canstar.com.au/home-loans/)
5. [Australian Taxation Office, 'Rental Property Deductions — Interest on Loans', 2025.](https://www.ato.gov.au/individuals-and-families/investments-and-assets/rental-properties/rental-expenses-you-can-claim/interest-on-loans)
6. [RateCity, 'Cashback Home Loan Offers Tracker', September 2025.](https://www.ratecity.com.au/home-loans/cashback)
7. [Finder.com.au, 'Average Home Loan Interest Rates in Australia — October 2025 Update'.](https://www.finder.com.au/home-loans/interest-rates)
8. [PremiumRea broker network: Big Four VP-level contacts and refinance facilitation.](#)

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Source: https://premiumrea.com.au/blog/mortgage-interest-rate-negotiation-australia
Publisher: PremiumRea (Optima Real Estate) — Melbourne buyers agent