Everything You Need to Know About Budgeting and Loans

A loan doesn't just get you into a property. It changes how you budget.

If you're financing an investment property in the ACT while renting elsewhere, every decision about where your income goes affects both your current cashflow and your capacity to grow a portfolio later. The structure you choose, the accounts you link, and the way you manage surplus income all determine whether the loan becomes a constraint or a tool.

How Investment Loan Repayments Affect Weekly Budgets

Your repayment obligation sits outside your rent. Both need to be paid, and one doesn't reduce the other.

On a principal-and-interest loan at current variable rates, a $500,000 investment property loan requires roughly $3,200 per month in repayments. If you're paying $2,400 per month in rent for your own home, your combined housing cost is $5,600 before any rental income is factored in. That rental income is taxable and typically assessed by lenders at 80 per cent of the gross amount for serviceability purposes, so a property returning $550 per week adds around $1,900 per month to your usable income after the lender's shading. The net weekly cost in that scenario is close to $900, assuming no vacancies and no maintenance.

That calculation changes if you use interest-only investment loans. The same $500,000 loan on an interest-only structure drops the monthly repayment to roughly $2,000, reducing your combined housing cost to $4,400 before rental income. Rental income of $1,900 per month brings the net cost down to around $600 per week. The difference between the two structures is $300 per week in immediate cashflow.

Interest-only terms typically run for five years. After that, the loan reverts to principal and interest unless you negotiate a further interest-only period. Lenders don't automatically extend. If your LVR is above 80 per cent or your circumstances have changed, renewal may be declined.

How Offset Accounts Reduce Interest Without Changing Repayments

An offset account linked to your investment loan reduces the interest charged without altering your contractual repayment.

If you hold $20,000 in a linked offset and your loan balance is $500,000, interest is calculated on $480,000 instead. At current variable rates, that saves roughly $100 per month in interest. The repayment amount stays the same, so the surplus goes toward paying down the principal faster on a principal-and-interest loan, or it accumulates as a buffer on an interest-only loan.

Not all lenders offer offset accounts on investment loans, and those that do may charge a higher annual fee or a marginally higher interest rate. The question is whether the tax outcome and cashflow benefit justifies the cost. On an investment loan, interest is deductible, so reducing the interest you pay also reduces your deduction. Holding $20,000 in offset saves $1,200 per year in interest but costs you roughly $450 in lost tax deductions if you're on the 37.5 per cent marginal rate, including Medicare levy. The net saving is around $750.

If the property is neutrally geared or close to it, the offset is more valuable. If it's heavily negatively geared and you're relying on the deduction to manage cashflow, keeping funds in offset may not be the right move. The alternative is to hold surplus funds in a separate high-interest savings account and leave the loan balance untouched, preserving the full deduction while still earning a return on your cash. You can read more about this in offset accounts on investment loans.

Split Loan Structures and Why Borrowers Use Them

A split loan divides your total borrowing across two or more accounts, each with its own rate type and repayment structure.

The most common version is a 50/50 split between fixed and variable. Half the loan is locked at a fixed rate for a set term, usually between one and five years. The other half remains on a variable rate with full offset and redraw access. This structure protects you from rate rises on the fixed portion while keeping flexibility on the variable portion.

Consider a buyer financing a $600,000 investment property in Gungahlin with a 10 per cent deposit. They split the loan into $300,000 fixed at 5.89 per cent for three years and $300,000 variable at 6.24 per cent with a linked offset. Monthly repayments on the fixed portion are roughly $1,800. Monthly repayments on the variable portion are $1,850, but if they hold $30,000 in offset, the effective interest portion drops by around $160 per month. The total repayment is $3,650, but the cost after offset benefit is closer to $3,490. If rates rise by 0.5 per cent over the next year, the variable portion increases by $90 per month, but the fixed portion doesn't move.

The trade-off is break costs. If you sell the property or refinance during the fixed term, you may be charged an economic cost based on the difference between your fixed rate and the current wholesale rate for the remaining term. On a $300,000 fixed loan with two years remaining, break costs can range from zero to several thousand dollars depending on market conditions. You can read more about this in split loans for rentvesting.

How Lenders Assess Your Income Against Your Commitments

Serviceability is tested at your loan's interest rate plus a 3.0 percentage point buffer, as required by APRA.

If your investment loan is priced at 6.24 per cent, the lender assesses your capacity to repay at 9.24 per cent. On a $500,000 loan, that means proving you can service monthly repayments of roughly $4,050, even though your actual repayment is closer to $3,100. The buffer applies to new loans only. Existing loans are assessed at their actual repayment amount, not at a buffered rate.

Your rental income is shaded to 80 per cent of the gross amount shown on the lease. If the property returns $550 per week, the lender treats it as $440 per week, or $1,900 per month. That's added to your salary or other income, and then all your commitments are deducted: rent, the new loan repayment at the buffered rate, any existing debt, living expenses, and HECS repayments if applicable. What's left is your surplus, and if it's positive, you meet the serviceability test.

Debt-to-income limits also apply. From 1 February 2026, ADIs can lend no more than 20 per cent of their new investor loans to borrowers with a DTI of six times gross income or higher. If your household income is $120,000 and your total borrowing across all loans is $720,000 or more, you fall into that 20 per cent cohort. Lenders manage their allocation carefully, and some will decline your application or price it higher to stay within their quarterly limit, even if you meet the serviceability buffer. This is one reason why maintaining a clean credit file and minimising non-mortgage debt improves your chances of approval at a competitive rate.

How Rent Increases and Loan Rate Changes Affect Your Position

Rental income and loan repayments move independently, and the gap between them determines your weekly cost.

If your tenant's lease renews and rent increases from $550 to $600 per week, your taxable rental income rises by $2,600 per year, and your after-shading income for serviceability purposes increases by roughly $170 per month. That improves your borrowing capacity for any future purchase, but it also increases your tax liability. At the 37.5 per cent marginal rate, the additional $2,600 in rental income costs you around $975 in extra tax, leaving a net benefit of $1,625 per year, or roughly $31 per week.

If your variable rate increases by 0.25 per cent at the same time, your repayment on a $500,000 loan rises by around $80 per month, or roughly $18 per week. The rent increase covers the rate rise with some margin left over, but the timing matters. If the rate rise happens before the lease renews, your cashflow tightens for several months. If you're holding surplus income in offset, that buffer absorbs the gap. If you're not, the shortfall comes out of your salary.

This is one reason why borrowers on variable-rate investment loans benefit from holding at least three months of repayments in accessible savings or offset. It smooths out the timing mismatch between rent reviews and rate changes and covers periods of vacancy without forcing you to dip into redraw or sell assets at short notice.

Where Surplus Income Should Go When Cashflow Is Positive

If your rental income exceeds your loan repayment and you're still covering your own rent comfortably, the surplus needs a purpose.

Paying down the principal on your investment loan reduces your debt but also reduces your deductible interest over time. If you're planning to purchase a second property or transition to owner-occupier in the next few years, a lower loan balance improves your serviceability and borrowing capacity. But if your priority is to maintain maximum deductions and preserve flexibility, keeping the loan balance intact and redirecting surplus income into offset or a separate savings account makes more sense.

Another use is to build your deposit for a second property. Lenders typically require genuine savings of at least 5 per cent of the purchase price, held in your account for at least three months. If you're earning $1,000 per month in surplus cashflow after all costs, that's $12,000 per year. Over two years, you accumulate $24,000, which covers a 5 per cent deposit on a $480,000 property plus some of the associated costs. You can read more about this in growing a rentvesting portfolio.

If you're not planning a second purchase in the near term, redirecting surplus income into your super as a concessional contribution or into the First Home Super Saver Scheme can reduce your taxable income while building equity in a tax-advantaged structure. The scheme allows you to save up to $50,000 in total and release it toward a future home deposit, though it's only available to first home buyers who haven't previously owned property.

How Loan Features Affect Ongoing Flexibility and Cost

Not all loans are built the same way, and the features you choose upfront affect how much control you have later.

A portable loan allows you to transfer the loan to a different property without refinancing, which matters if you sell your investment property and buy another within a short timeframe. Most lenders charge a discharge fee when you sell, typically between $300 and $500, and some charge a settlement fee on the new purchase. Portability lets you avoid both by keeping the same loan account and simply substituting the security. Not all lenders offer it, and those that do may require the new property to meet their lending criteria at the time of transfer.

Redraw allows you to access any extra repayments you've made above the minimum, but it's not the same as offset. Redraw is a facility, not an account, and the lender can change the terms, freeze access, or remove it entirely if your loan falls into arrears or if you breach the contract. Offset is a separate transaction account that remains under your control. If you're relying on surplus funds for short-term liquidity, offset is the more reliable structure.

Annual fees and package discounts also matter over time. A loan with a $395 annual fee and a 0.10 per cent rate discount costs you $100 more per year in fees but saves you $500 per year in interest on a $500,000 loan, for a net saving of $400. Some lenders waive the annual fee if you hold other products with them, such as a transaction account or credit card, but those products may carry their own fees or conditions. The calculation needs to account for the total cost across all linked accounts, not just the loan itself.

Call one of our team or book an appointment at a time that works for you. We structure loans for rentvesting buyers across the ACT and assess your full position before recommending a lender or product. If you're financing your first investment property or refinancing to improve your cashflow, we'll walk you through the options that match your budget and timeline.

Frequently Asked Questions