Using a second mortgage on an investment property to fund your business

Plenty of business owners are sitting on their best collateral without realising it. It isn’t the family home, and it isn’t the business itself. It’s the rental property bought years ago, which has quietly grown in value while the investment loan has barely moved.

A second mortgage lets you use that equity for the business without refinancing the investment loan or touching your home. This guide covers what’s different when the security is an investment property: the existing loan, the tenant, the tax angle and the exit. For the broader situation of releasing equity, see release equity from an investment property.

Can I get a second mortgage on an investment property for business purposes?

Yes. A private lender can take a second mortgage over a residential or commercial investment property that already carries a first mortgage. The existing lender stays in first place and the new loan ranks behind it, because registered mortgages rank in the order they’re lodged.

The loan must be for a business purpose: working capital, an ATO debt, equipment, stock, a deposit on business premises, a partner buyout or a project. Amounts run from $20k to $5m, depending on the equity and the exit, and no formal valuation is required.

Is an investment property better security than my home?

Often it’s the more comfortable choice, for the borrower and the lender alike.

Factor	Investment property	Family home
Effect if the exit slips	Pressure falls on an asset, not the roof over your head	Higher personal stakes
Exit by sale	Usually a natural, planned exit	Often a last resort
Income	Rent can help cover the first loan’s repayments	No rental income
Ownership	Frequently in a trust or company, already business-adjacent	Usually personal names
Who signs	Owners or trustee, and any guarantors	Every owner, including a non-business spouse
Tenancy	Lease must be allowed for in a sale	Vacant possession is simpler

Neither is “right”. Our residential vs commercial security page explains how different property types are viewed.

How does the existing investment loan affect a second mortgage?

The first loan shapes the deal more than anything else. Check these before applying:

• Balance and limit. Investment loans often have redraw or are lines of credit. Money the first lender can advance under its mortgage generally ranks ahead, so the limit counts, not just the balance.
• Interest-only expiry. If the investment loan is about to switch to principal and interest, the first loan’s repayments may rise mid-term. Budget for it.
• Cross-collateralisation. If your bank’s mortgage over the rental also secures your home or another property, the debt behind the rental may be larger than its own loan statement suggests. This affects both equity and payout on sale.
• Consent. Many first mortgages require the bank’s permission before further security is registered. The Queensland Government’s lending terms are a public example. Our guide to first mortgagee consent explains how to ask.
• Arrears. Any missed repayments on the investment loan should be declared upfront. They’re considered case by case.

Does having a tenant change anything?

The lease carries on. Your tenant keeps paying rent to you or your managing agent, and the second mortgage doesn’t alter their rights.

Where the tenancy matters is the exit:

• A sale with a tenant in place can suit investor buyers but may narrow the owner-occupier market.
• A sale with vacant possession depends on the lease’s end date and the notice rules in your state, which your agent or solicitor can confirm.
• Commercial leases can make a property more attractive to buyers if the tenant and term are strong.

Build those timelines into the loan term instead of assuming a quick sale.

How is the interest treated for tax?

This is where investment property owners most often trip up. The ATO’s rental guidance is clear that the security doesn’t decide deductibility; the use of the money does. In its own example, a loan secured against a rental property but used to buy a new home doesn’t produce deductible interest, because the home isn’t used to produce income.

Practical points:

• Keep business borrowings separate. The ATO says interest on a mixed loan must be apportioned between private and income-producing portions for the life of the loan, and refinanced funds take on the character of the original drawdown. A separate second mortgage used only for business keeps the record clean.
• Avoid redrawing on the investment loan for business needs unless your accountant is comfortable with the apportionment that follows.
• Ask your accountant how interest on business-use funds is treated in your structure, especially if the property owner and the business are different entities.

Which interest structure suits a rental property?

Rent already has a job: helping meet the first loan’s repayments, council and strata charges and the other outgoings. Stretching it further is rarely wise. Interest on the second mortgage can be prepaid or capitalised, so there may be no monthly repayments on it during the term, as explained in prepaid or capitalised interest.

Capitalised interest grows the balance, so check that the equity left at the end still comfortably covers both loans and the sale costs.

What exits work when the security is a rental?

The strongest exits, roughly in order:

1. Sale of the investment property, with the tenancy timeline built in.
2. Refinance to a bank, once the business’s figures or credit position support it.
3. A business event, such as a contract payment, an asset sale or a business sale settling.
4. Sale of another property in the portfolio.

Each needs a date and evidence. A second mortgage is typically shorter-term, so the exit should sit comfortably inside it.

Illustrative example: a Newcastle joinery business needs $250k to clear an ATO debt and buy a CNC machine. The director’s family trust owns a rental townhouse that would realistically sell for about $900k, with an interest-only investment loan of $420k. Illustrative: if the combined borrowing limit were set at 70%, total debt of up to $630k would leave room for a second mortgage of about $210k, so the business takes $200k against the townhouse and funds the balance from cash flow. Interest is capitalised, the trust’s bank gives consent, and the exit is a planned bank refinance after the next two quarters of BAS.

What does the lender look at in the rental itself?

The property is assessed directly. A specialist considers the location, the type of dwelling or building, its condition, the title and recent nearby sales, then forms a view of what it would realistically sell for. A few features of investment stock deserve a mention:

• Strata units. Building size, the owners corporation’s position and any known defects can affect how quickly a unit sells. Have the latest strata levy notice handy.
• Specialised rentals. Student accommodation, serviced apartments and very small units appeal to a narrower group of buyers, so the exit needs extra thought.
• Commercial rentals. The tenant, lease term, options and rent review terms matter, because they drive what an investor buyer will pay.
• Regional and rural rentals. Considered case by case, with more weight on the depth of the local market.

Which documents are specific to an investment property?

On top of the usual ID and entity paperwork, have these ready:

• the current lease, or a summary from your managing agent showing rent, term and expiry;
• a recent investment loan statement showing balance, limit, redraw and any interest-only expiry date;
• details of any other property tied to the same bank loan;
• the latest strata levy notice, if it’s a unit or townhouse;
• evidence of the exit, such as an agent’s appraisal and campaign plan for a sale.

Our guide to documents for a private mortgage lists the general paperwork.

Who signs when a trust or company owns the rental?

The owner of the property signs the mortgage. For a trust, that’s the trustee, and the trust deed needs to permit borrowing, mortgaging and guarantees. For a company, the directors sign. Where the property owner isn’t the business borrowing the money, guarantees and third-party arrangements come into play. Our page on company or trust-owned property covers the paperwork.

At a glance

• Security: your rental property, behind the existing investment loan.
• Purpose: business only.
• Amount: $20k to $5m, set by equity and exit.
• Interest: can be prepaid or capitalised.
• Assessment: no formal valuation required.
• Key checks: first loan limit, cross-collateralisation, consent, tenancy, tax treatment.

Rental property with equity to spare? See if you qualify

If your investment property has grown and your business needs funds, a short enquiry is the quickest way to learn what’s realistic. A specialist looks at your enquiry personally, including how the existing investment loan is structured.

There’s no credit check to enquire, and your details aren’t spread around a list of lenders. Our lending partner fundU lends directly. Give accurate figures for the property, the investment loan’s balance and limit, and anything else secured on it, because that’s what gets you the right answer first time.

See what your rental property could fund in about 60 seconds, or ask a specialist to check your structure first.