Need to file an SA Tax Return? Or claim a CIS tax rebate. Sole traders - get full support on Self-Employment Tax now! You will receive free advice on your tax status, and full support on your SA Tax Return - apply online and fix your self-employment tax now! Please NOTE: You will also get a FREE tax calculation! All we need is 3 figures for the relevant tax year - gross income, business expenses and CIS tax paid (if applicable).