The figures from your employment, provided on your P60 annually, will go directly on your Individual Self Assessment Tax Return. Quick File will help you manage your sole trader income and expenses and provide you with the figures for or you accountant to enter on your tax return, we would recommend speaking to an accountant if you unsure on how to complete your tax return.
That said, I have prepared a rough Tax Calculation for 2012/13 (year ended 5 April 2013) which is as follows:
Income received (before tax taken off)
Total from all employments: £50,000
Profit from self-employment 15,000
Total income received: £65,000
minus Personal Allowance: (£8,105)
Total income on which tax is due: £56,895
Income Tax calculated on total income above:
Pay, pensions, profit etc. £34,370 @ 20% = £6,874.00
£22,525 @ 40% = £9,010.00
Total income on which tax has been charged: £56,895
Income Tax charged: £15,884.00
Plus: Class 4 National Insurance contributions: £7,395 @ 9% = £665.55
Income Tax and Class 4 National Insurance contributions: £16,549.55
Minus: Tax deducted:
From all employments, UK pensions and state benefits: (£14,037.00) (estimated, obtain correct figures from P60)
Total tax deducted (£14,037.00)
Balance of Income Tax and Class 4 National Insurance contributions due: £2,512.55