Grandfathered vs new investments: get record‑keeping right

Key Takeaway

This article explains how Australians should track grandfathered vs new investment properties as negative gearing and CGT rules change from 1 July 2027, when residential rental losses on many new established dwellings will be quarantined. It outlines a step‑by‑step record‑keeping system: separate loan splits, distinct offset accounts, labelled folders and a per‑property schedule. A worked example shows how this prevents misclaimed wage-offset deductions and supports accurate tax returns and refinance decisions.

From 1 July 2027, many investors will have some properties under old negative gearing/CGT rules and others under the new regime, so you must keep property-by-property records that clearly show which tax rules apply and which loan relates to what.

If you don’t, you risk claiming the wrong deductions, overpaying tax, or having to rebuild years of records when the ATO asks questions.

Spreadsheet mapping investment properties to loan splits under old and new rules A simple spreadsheet can keep grandfathered and new investments clearly separated for tax purposes.

1. What “grandfathered” vs “new” really means

Grandfathered investments are properties where the old rules continue to apply because you owned them before the reform cut‑offs (for example, a residential investment bought before 12 May 2026 and held through 1 July 2027).

New investments are properties bought under the new rules, especially established dwellings purchased after the key dates where:

Rental losses are quarantined to rental income and capital gains, not wages.
CGT concessions are reduced or reshaped.

By 2028, many clients will hold both:

A pre‑2026 investment with full negative gearing against salary.
A 2027 purchase where losses can’t reduce wage income.

That mix is why record‑keeping suddenly matters a lot more.

For any established residential property bought after 12 May 2026, model cashflow assuming no wage‑offset negative gearing from 1 July 2027 and use pre‑tax cashflow as the key decision metric.

If you need help choosing investments under the new rules, see How To Rethink Investment Property Choice When Tax Rules Tighten.

2. The core rule: one loan story per property

The ATO doesn’t care which property secures a loan.

They care what the borrowed money was used for.

So your system needs to show, clearly:

Which loan split funded which property and costs.
Which tax regime that property sits under (grandfathered vs new).

Practical loan structure

Where possible:

Have one primary loan split per property.
Keep equity‑release splits separate, each with clear notes about which property they funded.
Avoid cross‑collateralising everything together unless a lender gives you no choice.

This mirrors the advice we give in leverage pieces like How Property Leverage Really Works.

Worked example

2024: You buy Unit A (grandfathered). $500k loan, Split A1.
2027: You release $120k equity from your home (Split H2) and buy Unit B (new rules) with a separate $480k loan (Split B1).

Your spreadsheet should show:

Split A1 → Unit A (grandfathered)
Split H2 + Split B1 → Unit B (new rules)

Losses on Unit A can still offset wages.

Losses on Unit B are quarantined to rental/CGT from Unit B (and possibly other post‑reform dwellings, depending on final law).

3. A simple record‑keeping system you can set up this week

Busy? Here’s the 80/20 version. ### Step 1: Label everything In your internet banking: - Rename loan splits: “Inv – Unit A – GF – Split A1”, “Inv – Unit B – NEW – Split B1”. - Tag offsets: “Offset – Inv – Unit A”, “Offset – Inv – Unit B”. In your calendar or notes app, create a one‑page portfolio map listing: - Property address - Purchase date - Type (new build/established, residential/commercial) - Tax regime: GF (grandfathered) or NEW - Relating loan splits and offsets ### Step 2:…

Frequently asked questions

Do I need a separate loan for every investment property?▾

You don’t legally need a separate loan for each property, but separate splits make tax and refinancing far cleaner. The ATO looks at what the borrowed funds were used for, not just which property secures the loan. If each split clearly relates to one property, your accountant can claim interest correctly and you avoid complicated apportionment.

How do I tell if a property is grandfathered under the negative gearing reforms?▾

In broad terms, a property is grandfathered if it was acquired before the key reform dates and meets the criteria set out in the final legislation (for example, many pre‑12 May 2026 investments held through 1 July 2027). Because details can be complex and still evolving, check the acquisition date, property type and your personal situation with your tax adviser.

Can I fix messy mixed‑purpose loans after the rules change?▾

Yes, you can often clean things up by refinancing into clearer splits that match specific properties. This doesn’t rewrite history, but it improves tracing going forward. Your accountant may still need to apportion interest for earlier years, but over time clearer structures reduce admin, errors and audit risk.

Speak with a specialist advisor

Confidential consultation, bespoke advice for your situation.

How To Track Grandfathered vs New Investments As Tax Rules Change