Can I be employed and a CIS subcontractor at the same time?

Can I be employed and a CIS subcontractor at the same time? Yes. In 2026-27 you can hold a PAYE job and do self-employed CIS work, but the CIS side needs a Self Assessment tax return, where your wages and profit are added together and your deductions set against the bill. Your employer does not deal with the tax on it. Your CIS income goes on your own Self Assessment return, and the employer keeps taxing your wages through PAYE using the tax code HMRC gives them. CIS 340 says the scheme does not apply to a contract of employment, and that status depends on the terms of each engagement. A separate self-employed contract can sit under CIS, but the employment itself cannot. Your job usually uses up your £12,570 personal allowance, so your self-employed profit is taxed from the first pound. Someone with only CIS income gets the allowance against their profit, so more of their 20% deduction comes back. Read the full answer, with every source, at rightotax.co.uk.