For the last few years HMRC have been offering Personal Tax Accounts which give you access to, and oversight of, your tax situation. This service will also show you your National Insurance information and State pension details. If relevant, the service will show Tax Credits and Child Benefit details.
For further information and to setup your Personal Tax Account visit the HMRC’s website:
Personal tax accounts - HMRC's online service for individuals
This short video tells you how to sign up to your own personal tax account, and how it helps you deal with your HMRC affairs online at a time that suits you, on a device of your choice.