Buying a New Home Before Selling Your Old One?

Here’s What You Must Know About Australia’s CGT Rules

Buying your next home before you’ve sold your current one is becoming increasingly common — especially in a competitive market. However, it’s important to understand how this affects your Capital Gains Tax (CGT) position.

Under Australia’s CGT rules, you normally can’t treat two properties as your main residence at the same time. But there is a generous concession that can help you avoid an unexpected tax bill during the transition.

The Six‑Month Overlap Rule

If you move into your new home and it genuinely becomes your main residence, you’re allowed to treat both homes as CGT‑exempt for up to six months.

This overlap period gives you time to sell your existing home without losing your main residence exemption — a valuable tax benefit.

A Simple Example

If you:

• Buy your new home: 1 February 2026

• Sell your old home: 1 July 2026

…both homes can remain fully CGT‑exempt for the five‑month overlap — as long as the conditions are met.

Key Conditions for the Six‑Month Concession

To qualify, you must meet both of the following criteria:

1. Your old home must have been your main residence

   It must have been your main residence for at least 3 months in the 12 months before you sell it.

2. Your old home cannot have been used to produce income

   This means no renting, no Airbnb, and no business use that claims occupancy deductions during any period you weren’t living in it within the 12‑month window.

If your old home was rented during this period, you may lose the six‑month concession and could be subject to partial CGT. In this case, the CGT calculation may be based on the market value at the time the property was first rented — which can significantly affect the outcome.

Other Concessions That May Help

Even if you don’t qualify for the six‑month rule, there are other ways to preserve your CGT exemption:

The Absence Rule

Under this rule, you can continue to treat your former home as your main residence even if you move out and rent it.

The Building Rule

If you buy land or plan to build a new home, the ATO allows you to treat the land as your main residence during construction.

Why Advice Matters

These concessions can interact in complex ways, and the right outcome depends heavily on your specific circumstances. Getting professional guidance ensures you don’t accidentally trigger a CGT liability when transitioning between homes.

Final Thoughts

Buying a new home before selling your existing one doesn’t have to be a tax headache.With the six‑month overlap rule and other CGT concessions, many homeowners can maintain full CGT exemption — but only if the rules are applied correctly.