What Tax Mistakes Quietly Drain Returns From Multiple Rentals?

One rental is manageable. Two or three is where the paperwork starts to fight back.

Rent rolls, loan statements, body corporate notices, repair invoices, and depreciation schedules stop sitting neatly in one folder. That’s usually when small tax mistakes stop being small.

The ATO has flagged rental claims as a high-error area for years. Plenty of investors still get things wrong, even with an agent. With multiple properties, the same error can repeat across every holding. That quietly cuts after-tax returns, and it can create a bigger mess when you sell.

Here’s where money typically leaks.

Treating loan interest as fully deductible when it isn’t

Interest is often your biggest rental deduction. It’s also easy to overclaim once finance gets rearranged.

Redraw is a common trap. You redraw for a private cost (a car, school fees, a holiday) and keep claiming the full interest bill. You shouldn’t. Interest is only deductible to the extent the borrowed money is used to earn rent. Once private spending sits in that loan, you need to apportion. That split continues for the life of the loan.

Cross-collateralised loans make this harder. One facility across the home and two rentals can look tidy at the bank. At tax time, it’s a tracking job. If funds move between properties, or equity funds a purchase plus private costs, keep a clear trail of what interest relates to income-producing use.

Borrowing costs get mishandled too. Loan establishment fees, LMI, and title search fees are generally claimed over five years or the life of the loan, whichever is shorter. They’re not always an automatic year-one write-off.

If your loan structure has changed since settlement, don’t assume last year’s interest claim still holds.

Mixing up repairs, maintenance, and capital work

This is still one of the most common rental errors of the ATO flags.

Repairs restore something that wore out or broke while the property was rented. Examples:

fixing a leaking tap
replacing damaged guttering like-for-like
repairing a broken stove

These can usually be claimed in the year you incur the cost.

Improvements make the property better or different. Examples:

a full kitchen upgrade
adding a deck
replacing a basic bathroom with a higher-spec fit-out

These are capital. You don’t claim them as an immediate deduction. They usually go through capital works or depreciation over time.

Initial repairs are another problem. Work needed to fix defects that existed when you bought the place is generally capital, even if it looks like maintenance. Those costs often sit in the CGT cost base instead of coming off this year’s income.

With multiple rentals, people batch invoices and claim everything as “repairs.” The ATO looks at the nature of the work, not the label on your spreadsheet. Keep quotes and invoices clear, and separate capital items before you lodge.

Skipping depreciation and capital works claims

Depreciation is a non-cash deduction. You don’t spend the money again each year to claim it. That’s why busy landlords miss it.

Two buckets matter:

Plant and equipment (Division 40): carpets, blinds, air conditioners, appliances
Capital works (Division 43): building structure and certain fixed improvements, often at 2.5% a year where eligible

Older properties can still produce claims. Second-hand plant rules tightened years ago, but capital works may still apply. New assets you install after purchase can be depreciated.

Renovations change the schedule. If you refit a bathroom in property two and ignore the update, you leave deductions behind and muddy the cost base for later.

A quantity surveyor’s depreciation schedule is the practical starting point for most investors. Hand it to whoever prepares the return. Update it when you add assets or complete structural work.

Getting ownership shares and income reporting wrong

Legal ownership drives the split. If the title says 50/50, you generally report 50/50, even if one person manages everything or earns more.

Don’t have one owner report the whole property “to keep it simple.” Both owners need to report their share. ATO data matching with property managers and platforms makes uneven reporting easier to spot.

Report gross rent, then claim expenses. Reporting net rent and claiming the same outgoings again is a known error.

Agent statements help, but still include amounts you paid direct:

council rates
insurance
land tax
repairs you arranged yourself

Claiming travel that individuals can’t claim

Since 1 July 2017, individual investors generally can’t claim travel for residential rentals. That includes:

flights
petrol and tolls
accommodation
meals tied to inspections, maintenance visits, or collecting rent

This still catches people with interstate holdings. Flying north twice a year to check on the units feels like a business cost. For most individual landlords, it isn’t deductible. Those costs usually don’t go into the CGT cost base either.

There are narrow exceptions, such as certain entities or a genuine business of letting properties. Most private investors with a handful of rentals won’t meet that bar. If travel is material in your numbers, get advice before you claim it.

Letting land tax, vacant periods, and private use blur the edges

Land tax is assessed by the state, but it’s still a deductible holding cost when the property is used to produce rent. Investors with properties in more than one state sometimes miss it, or claim it against the wrong property.

Vacant periods are fine if the property is genuinely available for rent at market rates.

Problems start when a place sits empty for personal reasons, is blocked out for family use, or isn’t actively marketed. Expenses may need apportioning for private-use periods.

Holiday homes used partly by the family are a regular focus area. Keep:

booking calendars
advertising evidence
a clear split between income-producing and private days

Stamp duty is another recurring mistake. Outside specific ACT leasehold settings, stamp duty is generally not an immediate rental deduction. It usually forms part of the CGT cost base when you sell.

Record keeping that doesn’t scale with the portfolio

One property can survive on a shoebox and good memory. Three properties can’t.

At minimum, keep:

agent rental summaries for each property
loan statements showing redraws and the purpose of funds
invoices that separate repairs from capital work
up-to-date depreciation schedules
land tax assessments by state
records of private use or below-market arrangements
settlement statements and improvement costs for CGT

The ATO can amend assessments and apply penalties and interest where claims don’t hold up. A taxation accountant who regularly handles multi-property returns will usually build the year around source documents, not around what felt deductible in June. That process matters more once properties, loans, and ownership structures stop looking identical.

CGT surprises when a property finally sells

Holding costs get most of the attention during ownership. Sale is where earlier shortcuts surface.

Watch for these:

Capital works claimed over the years can reduce the cost base and increase the taxable gain
Depreciating assets have balancing adjustment rules
Missing improvement records can understate the cost base and leave you overpaying tax

The 50% CGT discount may apply for individuals who held the asset more than 12 months, but only after cost base and other adjustments.

Main residence rules get messy if a home later becomes a rental, or if you relied on the absence rules. Investors who moved out, rented the place, and assumed full exemption often find the exemption is partial or time-limited.

When two or three sales happen across a few years, basis tracking becomes portfolio work. That’s where a property investment accountant earns their fee: reconciling depreciation history, improvement invoices, and ownership changes before contracts exchange, not after the assessment issues.