Perhaps things have moved on in the last couple of years but the following was true in 2015, and didnt include added bonuses like the extra employment expenses you can legally claim which you cant as a PAYE employee. Was easy to legally reduce that taxable income down even further to leave the self employed person around 20% effective tax.
Salary Limited Company one shareholder Limited company two shareholders
Gross income £80,000 £80,000 £80,000
Salary £71,282 £8,060 £16,120
Gross profit before tax N/A £71,940 £63,880
Employers N.I. £8,717.53 N/A N/A
Employees N.I. £4,758.85 N/A N/A
PAYE £17,712.59 £0 £0
Corporation tax N/A £14,388 £12,776
Net profit N/A 57,552 £51,104
Tax on dividends (income tax) N/A £9,373 £2,640
Income after taxes £48,811 £56,239 £64,584
Effective Total Tax Rate 39.0% 29.7% 18.9%