Home-office deduction

Work out your SARS home office deduction in two numbers: the floor area of your office and your home running costs. This calculator applies the section 23(b) floor-area apportionment – office square metres divided by total square metres – to your rent (or bond interest), rates, electricity and cleaning, and shows you the exact rand deduction with the arithmetic laid out. No estimating, no guessing the percentage: enter your measurements and your year's costs, and it returns a figure you can put on your ITR12 and defend if SARS asks.

Open the Home Office calculator →

What it calculates

The home office deduction lives at the intersection of three sections of the Income Tax Act, and the calculator handles each one:

• Section 11(a) – the general rule that lets you deduct expenses incurred in producing your income.
• Section 23(b) – the gatekeeper. You may only claim premises costs if a part of your home is used regularly and exclusively for your trade and is specifically equipped for it. A spare room that is only your office qualifies; the dining table where the family also eats does not.
• Section 23(m) – restricts what salaried employees can claim, but is more permissive for income that isn't pure remuneration. This is why freelancers and the self-employed have a stronger home-office position than ordinary employees.

If you clear the section 23(b) gate, the calculator works out your apportionment fraction and applies it to the costs that relate to the premises: rent or bond interest, rates and taxes, electricity, repairs and cleaning. (Costs that aren't connected to the premises – such as wear and tear on your equipment and furniture – aren't apportioned by floor area; run those through the Wear and Tear calculator instead.)

The floor-area apportionment, shown

SARS accepts apportionment by floor area: the square metres of your home office divided by the total square metres of your home. That fraction is then applied to your premises costs for the year.

Apportionment % = office m² ÷ total m² Home office deduction = apportionment % × premises costs

So a 12 m² office in a 100 m² home gives a 12% apportionment. If your rent, rates and electricity for the year total R96,000, your deduction is 12% × R96,000 = R11,520. The method is the point – the calculator does this for your real numbers and shows each step, so the deduction on your return is traceable rather than a round guess.

A worked example

Thandi freelances as a copywriter from home. Her study is 15 m² in a 120 m² flat, used only for work and properly equipped.

• Apportionment: 15 ÷ 120 = 12.5%
• Premises costs for the year: rent R84,000 + electricity R9,000 + rates R3,000 = R96,000
• Home office deduction: 12.5% × R96,000 = R12,000

That R12,000 comes off her income before her marginal rate is applied – so on a 31% marginal rate it saves her roughly R3,720 in tax. The calculator produces this figure, the percentage and the breakdown in one pass.

New to this? Read the guide first

This page is for working out the number. If you want the full reasoning – who qualifies, how the home office fits alongside your other freelance deductions, and how it flows into your assessment – read the Freelancer and side income tax guide, which covers the home office in context. Then come back here to calculate it.