bedped

Hello I have a ltd company (am sole employee and Director) which I have been paying myself from monthly (using basic PAYE tools). This income from my ltd company is my only income. I have received a notice to file self-assessment, and when going through it preliminarily, I see it I'm being taxed my on the income I've paid myself over the year PLUS the turnover of the ltd company. What have I done wrong? And how best to resolve? Thank you very much for your advise.