HMRC issues booklets explaining how PAYE works, these can be obtained from your tax office or via HMRC's website which has downloadable PDFs of all of its main documents.
The main documents you need to operate PAYE are:
Form P11 – a deduction working sheet for each employee
PAYE Tables (there are two books of tax tables):
Table A – Pay Adjustment Tables – shows the amount that an employee can earn in any week or month before the payment of tax
Tables B to D and LR – Taxable Pay Tables – show the tax due on an employee's taxable pay
Form P45 – given to an employee on leaving
Form P46 – used when a new employee does not have a P45 from previous employment (e.g. a school leaver starting work for the first time)
Form P60 – used to certify an employee's pay at the end of the tax year
Form P35 – the year-end declaration and certificate which summarises all the tax and National Insurance deductions from employees for the tax year
Form P6 – the tax codes advice notice issued by the Inspector of Taxes telling you each employee's tax code
Arriving at employee tax deductions
You will probably want to employ an accountant, book keeper or payroll agency to do this for you. However, if you want to do it yourself or just oversee the job more closely then here's the basic method:
Add the week's or month's gross pay to the previous total of gross pay to date, so as to show the total gross pay to date and including this week of the tax year
By checking the tax code number of the employee on Table A, arrive at the figure of tax-free pay for that particular week or month.
Deduct the amount of tax-free pay from the total pay to date, to get the amount of taxable pay.
By using Table B work out the tax due on the total taxable pay for the year to date. Then make the appropriate deduction to allow for the tax due.
Deduct the amount of tax already accounted for in previous weeks or months, from the total tax due, to work out the tax due for the week.