Why the PAYE keep changing ? Paye is pay-as-you-earn

hi all
PAYE (or pay-as-you-earn) is a payroll deduction system in which tax is deducted from a person's income when paid by the employer. The amount withheld is determined by a tax code which applies the taxpayer's individual tax liabilities. The PAYE system is also used to collect national insurance contributions.
PAYE is intended to collect the correct amount of tax on an employee's pay automatically, so no tax return and no further payment of tax is required.

Now the Question...
What will be the paye and NI for each month for example for a person making £80K per year ?

Is paye constant for the tax year? or it will change once you reach  cumulative salary 
22k ?

You must give every employee who has paid PAYE or NICs and is still working for you at the end of the tax year, a certificate showing their pay, PAYE and NIC's details. Finally you must give your employees a copy of the information you have given the Inland Revenue about their expenses payments and benefits provided

What is the end of the tax year in UK ? Do you get the certificate by the end of it ?


See example below how to Paye keep changing ... This is just my imagination..
I really dont know ..

Annual Salary    £80,000  ( just Example  )
    
   Annual Salary   80,000

    YTD Salary   Monthy Wage                   NI   PAYE   
    £6,666.67    Jul-06    £6,666.67       290   1467   22%
    £13,333.33    Aug-06    £6,666.67       290   1467   22%
    £20,000.00    Sep-06    £6,666.67       290   1467   22%
    £26,666.67    Oct-06    £6,666.67       290   1467   22%
    £33,333.33    Nov-06    £6,666.67       290   1467   22%

    £40,000.00    Dec-06    £6,666.67       290   2667   40%
    £46,666.67    Jan-07    £6,666.67       290   2667   40%
    £53,333.33    Feb-07    £6,666.67       290   2667   40%
    £60,000.00    Mar-07    £6,666.67       290   2667   40%

The first £2,150 of your taxable income is taxed at 10%.
The next £31,149 is taxed at 22%.
Any further earnings are taxed at 40%.

I'm interested in the answer to this, too.  My husband's income tax withholding changes by up to a factor 3 (up or down) from month to month and we can't figure out why.  He's tried contacting his payroll department multiple times, but they haven't bothered getting back to him.  Is this normal?  He earns the same salary each month, with the exception of an additional £50 or so for occasional overtime. 

UK PAYE is cumulative, but it assumes that you get one-twelth of your annual personal allowance and tax rate bands each month.

So it will change in May once the new UK tax year has started, but unless HMRC issue a new code to the employer it will not otherwise change radically each month.  If it seems to do so then your payroll department are the right folks to ask.

UK PAYE is cumulative, but it assumes that you get one-twelth of your annual personal allowance and tax rate bands each month.

Does it change once you pass cumulative salary of  £31,149 to 40% from 22% ?

Thanks
Kal


Our Payroll  said the tax is cumulative and does change when hitting the £31,149 to 40%.

Does it change once you pass comulative salary of  £31,149 to 40% from 22% ?

If it's cumulative, then no.  It would be similar to the way withholdings were done in the US.  They will take your monthly pay and extrapolate your annual income, then choose your tax bracket and calculate your tax withholding based on your projected annual income. 


Thanks guya - he'll have to keep trying to get in touch with payroll, because these swings each month are crazy.