Section 12B Solar Deduction for Small Businesses and Sole Proprietors

The mechanics are identical to large companies: 125% of the qualifying solar cost is deducted from taxable income in the year of first use. There is no minimum system size or minimum spend.\n\nA small business investing R200,000 in a 15 kW system claims a R250,000 deduction. At 27% company tax, the saving is R67,500. Sole proprietors claim against their marginal tax rate, which may be higher — a taxpayer in the 41% bracket saves R102,500.

Sole proprietors claim Section 12B on their personal income tax return (ITR12) as a business deduction. The solar system must be used for trade purposes, typically installed at business premises or a qualifying home office.\n\nThe deduction reduces taxable income, and the saving depends on your marginal tax rate. Higher-income sole proprietors (earning above R857,900, in the 41% bracket) receive a larger percentage saving than those in lower brackets.\n\nImportant: the solar must be used primarily for trade. A system installed at home that powers both personal and business use requires an apportionment.

A 10 kW system costing approximately R140,000 generates around 1,400 kWh per month. At R3.10/kWh, that's R4,340 in monthly electricity savings (R52,080 annually).\n\nWith Section 12B, the R175,000 deduction delivers R47,250 in tax savings (at 27%). Combined with first-year electricity savings, the small business recovers nearly R100,000 of the R140,000 investment in year one.\n\nPayback with Section 12B: approximately 10 months. Without it: approximately 2.7 years. This transforms a modest investment into a compelling quick-return opportunity.

Start with a site assessment from a reputable installer. For small systems, this is typically free. Get itemised quotes from 2-3 installers.\n\nEnsure the invoice clearly lists solar-specific components (panels, inverter, mounting, cabling) as SARS may request this detail. Have the installer provide a commissioning certificate when the system goes live.\n\nGive the invoice and commissioning certificate to your accountant at tax time. They'll include the Section 12B deduction in your annual return.