Higher tax rate confusion

Can anyone tell me I will be receiving a pension lump sum in August 24 which will take my income to 100000 my income is normally 30000 how long do you have to pay the higher income tax for thanks for any help provided

Hi
Please have a look at Income Tax rates and Personal Allowances for details of the different tax bands.  The higher rate tax band changes to the additional rate band at £125140, so any taxable income above this figure is tax at the rate of 45%.