Higher rate tax on pension lump sum

I am withdrawing a lump sum from one of my pensions. I am a higher rate tax payer. Will the taxable element be taxed at higher rate, and if not how do I repay underpayment of tax. I do not self declare for tax purposes, but pay through PAYE of my employer that I will continue to be paid by

Hi,
Please see the link below
Find out the rules about Individual Lump Sum Allowances
Thank you.