As part of HMRC's digitisation campaign, an online trial allows company car drivers to make changes to car and fuel benefits that will affect their tax codes. It is important to ensure the benefits included in your tax code are as accurate as possible or large under or overpayments of tax may arise. For information on how to amend your tax code visit the link below. Alternatively if you would like help checking your tax code please do get in touch. Internet link: GOV.UK