Simple hacks to compare investment loans as a first buyer

Comparing investment loans works differently to owner-occupied borrowing

When you compare investment loans, you're looking at how each product handles rental income, tax deductions, and the flexibility to manage vacancy periods or rate changes. Lenders assess investment borrowing differently to home loans, and the features that matter most depend on whether you need cashflow breathing room or want to maximise deductible interest.

Consider a single-income buyer in Melbourne earning around $85,000 who decides to purchase a one-bedroom apartment in Clayton as an investment while continuing to rent closer to the city. The rental income won't cover the full loan repayment, but the tax deduction from negative gearing reduces the gap. When comparing loan options, this buyer needs to know how much of the rent each lender will include in serviceability calculations, whether the loan allows for periods without tenants, and what happens if rates climb mid-lease.

Some lenders only count 80% of expected rental income when calculating how much you can borrow, while others allow up to 100% if the property is already tenanted and you provide a signed lease. That difference can shift your borrowing capacity by tens of thousands of dollars. If you're on a single income, that margin often determines whether you can proceed with the purchase or need to adjust your deposit or property choice.

What loan features actually matter for property investors on one income

You want a loan structure that gives you room to adapt when circumstances change. Interest-only repayments, offset accounts, and the ability to switch between fixed and variable rates are the three features that make the most difference when you're managing an investment property on a single income.

Interest-only repayments reduce your monthly cost, which helps if rental income doesn't quite cover your loan commitment. The lower repayment also means you're not forced to sell during a vacancy period or if your tenant leaves unexpectedly. After the interest-only term ends, you can choose to extend it, switch to principal and interest, or refinance to another lender offering a fresh interest-only period.

An offset account linked to your investment loan lets you park savings or rental income and reduce the interest you pay without losing access to the funds. If you're claiming interest as a tax deduction, an offset account is more flexible than making extra repayments directly onto the loan, because withdrawing from an offset doesn't affect your deduction, whereas redrawing from the loan can create complications with the ATO.

Splitting your loan between fixed and variable portions gives you predictability on part of your repayment while keeping access to offset and redraw features on the variable portion. Not all lenders allow splits on investment loans, and some that do will charge separate fees for each portion, so this is worth comparing upfront.

How to calculate what an investment loan will actually cost you each month

Your repayment depends on the loan amount, the interest rate, and whether you choose interest-only or principal and interest. Most lenders will show you an indicative rate online, but the actual rate you receive depends on your deposit size, your income, and the lender's assessment of the property you're buying.

If you're borrowing at an LVR above 80%, you'll also need to factor in Lenders Mortgage Insurance, which is a one-off cost usually added to your loan balance. On a single income, LMI can push your total borrowing above what feels manageable, so some buyers choose to wait and save a larger deposit rather than proceed with a smaller one and carry the insurance cost for the life of the loan.

Rental income reduces your net cost, but you also need to set aside an amount for vacancy periods, maintenance, and strata fees if you're buying an apartment. A unit in Clayton near Monash University might achieve strong rental demand during semester, but you could face a gap over summer if your tenant is a student. When comparing loans, look at whether the repayment structure gives you enough buffer to cover a month or two without rent.

Interest-only versus principal and interest for first-time investors

Interest-only loans suit buyers who want to minimise their out-of-pocket cost while maximising their tax deduction. You're not paying down the loan balance, so your monthly repayment is lower and the full amount of interest you pay remains deductible.

Principal and interest repayments mean you're gradually reducing what you owe, which builds equity faster and reduces the total interest you'll pay over time. The downside is a higher monthly repayment, which can strain cashflow if you're on a single income and already covering rent on the property you live in.

Many first-time investors on one income start with an interest-only period to establish a foothold, then switch to principal and interest once their income increases or they've built enough equity to feel comfortable with the higher repayment. The option to switch without refinancing is worth checking when you compare lenders, because some will let you change repayment type with a phone call, while others treat it as a full loan variation with fees attached.

Variable versus fixed rates for investment property finance

Variable rates move with the market, which means your repayment can increase or decrease depending on what the Reserve Bank does with the cash rate. You'll usually get access to offset accounts, unlimited extra repayments, and the ability to refinance without penalty, which makes variable loans more flexible if your situation changes.

Fixed rates lock in your repayment for a set period, typically between one and five years. You know exactly what you'll pay each month, which helps with budgeting, but you'll lose access to offset accounts on most fixed loans and you'll face break costs if you want to refinance or sell before the fixed term ends.

Some lenders offer discounted fixed rates on investment loans for new builds, which ties into the recent changes around capital gains tax and negative gearing. If you're comparing loans for a new apartment, check whether the lender offers a better rate or waives LMI for properties that qualify under the government's housing incentives.

What deposit size and LVR mean for your loan comparison

Most lenders will lend up to 90% of the property value for an investment purchase, but the interest rate and fees change depending on how much deposit you put down. At 80% LVR or below, you'll avoid paying Lenders Mortgage Insurance and you'll usually qualify for a lower interest rate.

If you're buying on a single income and using a guarantor loan to reduce your deposit requirement, some lenders will treat the guarantor portion differently and calculate your LVR as if you've put down a larger deposit. That can bring you under the 80% threshold and remove the need for LMI, even though you haven't saved the full 20% yourself.

Lenders also apply different serviceability buffers depending on your LVR. If you're borrowing at 85% or 90%, they might add a larger interest rate buffer when calculating whether you can afford the loan, which can reduce how much they're willing to lend. On a single income, that buffer often determines whether you can borrow enough to proceed with the property you've chosen or need to look at a lower price range.

How recent tax changes affect which loan features to prioritise

From 1 July 2027, negative gearing deductions on established residential properties purchased after 12 May 2026 will only offset income from other residential investments, not your salary. If you're buying an established apartment in a suburb like Clayton, you won't be able to claim the loss against your wage income, which reduces the tax benefit and changes the cashflow equation.

New builds remain exempt from this change, so buyers purchasing off-the-plan or newly completed properties can still claim the full deduction against all income. When comparing loans, consider whether the property you're buying qualifies as new, because that will influence how much of your repayment you'll recover through tax savings.

The capital gains tax changes also matter if you're planning to sell within a few years. Established properties purchased after Budget night will face a minimum 30% tax on gains from 1 July 2027, while new builds let you choose between the old 50% discount and the new indexed method. If you're weighing up loan options for a new apartment versus an older one, the tax treatment on exit could shift which property makes more sense financially, even if the loan features look similar.

Serviceability and rental income assumptions across different lenders

Lenders don't all treat rental income the same way. Some will only count 80% of the rent when calculating your borrowing capacity, while others allow 100% if you provide a signed lease or a rental appraisal from a licensed agent. On a single income, that difference can mean borrowing an extra $30,000 to $50,000, which might be the gap between affording the property you want and needing to compromise.

If you're buying in an area with strong rental demand, like near Monash University in Clayton or around the hospitals in Box Hill, providing evidence of comparable rents and low vacancy rates can help your case with lenders who take a more flexible approach. Some lenders also reduce the rental income they'll accept if the property is in a location they consider higher risk, such as regional areas or precincts with oversupply of similar apartments.

Your existing rent also plays a role in serviceability. If you're paying $450 per week to rent in the inner suburbs and the property you're buying will generate $400 per week in rent, the lender will factor in both outgoings when deciding how much you can borrow. Using an offset account or equity release strategy to reduce your future rental expense can sometimes improve your borrowing capacity, but this depends on your overall financial position and the lender's policy.

Refinancing investment loans when your circumstances or the market shifts

Your first investment loan doesn't need to be your last. Many buyers on a single income will start with whichever lender approves their application and offers a workable rate, then refinance to a different lender once they've built equity or their income increases.

Refinancing lets you access a lower rate, switch from interest-only to principal and interest, or consolidate other debts into your investment loan if that improves your cashflow. Some lenders also offer cashback incentives for refinancing customers, which can cover your switching costs and leave you with a few thousand dollars to put into an offset account or use for property maintenance.

If you're planning to expand your portfolio and purchase a second investment property, refinancing your first loan to release equity can provide the deposit for the next purchase without needing to save again from scratch. This approach works well if the property you already own has increased in value or if you've paid down enough of the loan to bring your LVR below 80%, because you can borrow against that equity without paying LMI on the second property.

Call one of our team or book an appointment at a time that works for you. We'll compare investment loan options across multiple lenders, explain how each product handles rental income and tax deductions, and help you structure a loan that fits your income and your plans for building wealth through property.

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