If your tax code is incorrect you could be paying more tax than you need to.
If you were previously employed in a company where you received benefits in kind it is likely that your tax code would have been decreased in order to automatically pay these throughout the year, or perhaps you underpaid tax in one year and this is being reclaimed through your tax code.
In order to ensure you have been given the correct tax code you should contact HMRC on 0845 3000 627.
You will need your National Insurance number and your company PAYE scheme reference.
They are open from 8am to 8pm Mon to Fri, and 8am to 4pm on Saturdays.