Business space at home: deductions now or tax later?

Only when an area of the home is set aside and used exclusively as a place of business and you can claim occupancy expenses such as mortgage interest, rates and insurance. Then the exemption does not cover the gain on that floor-area share. A desk in a room also used privately, or a study used for work you would usually do elsewhere, leaves the exemption whole.

No. The taxed share is the share of the home the interest would be deductible for, whether or not you claim it, and the ATO applies that test even when there is no mortgage. Leaving the deduction unclaimed gives up the deduction without reducing the gain.

Only the owner who runs the business. That owner claims occupancy expenses for the business share and loses that share of the exemption on their part of the gain. The other owner claims no occupancy expenses and keeps the full exemption on their share.

Rarely. The concessions need the home to be an active asset, and the test looks at the whole property, not just the business part. A home used mainly as a home usually does not qualify.

Up to 6 years for each absence if it earns income, such as rent, and with no time limit if it does not. While it is treated as your main residence, no other home can be, apart from up to 6 months when moving house. You and your spouse have one main residence between you at a time.

Not when it is for shared household expenses or family care: that is a domestic arrangement, so it is not income and nothing is deductible. It can be income, even from family, when it is rent for the use of the home under a lease or licence. If that rent is below market, deductions are apportioned, and the ATO accepts limiting them to the rent received. A lodger paying market rent is income in full, with deductions for their share of the home and that share of the gain outside the exemption.

Generally not: an employee claims running expenses, and there are no capital gains implications if that is all you claim. Occupancy costs are open to an employee only when the work needs a place of business, the employer provides no alternative place, and the area is used exclusively or almost exclusively for work. If you also run a business from home, its costs are claimed separately, as business expenses.

If you own an asset as an individual (or through a trust or partnership), the 50% CGT discount is generally replaced by indexation of the cost base and a 30% minimum tax on capital gains accruing after 1 July 2027; if you invest in an eligible new build, you can choose the discount instead. This is now law, under the Treasury Laws Amendment (Tax Reform No. 1) Act 2026. Your gains accruing before 1 July 2027 keep the discount, and your main residence exemption is unaffected. By default an asset held at that date is treated as sold just before 1 July 2027 at its market value: the gain to then keeps the discount and is taxed when you actually sell. You can instead choose an apportionment method the Minister sets, which so far is only a draft. The verdict here weighs the years to 30 June 2027; add the home's values for an estimate of later growth under the new rules.