Tax year to 5 April 2021
To the employee:
Please keep this certificate in a safe place as you will need it if you have to fill in a tax return. You also need it to make a claim for tax credits or to renew your claim.
It also helps you check that your employer is
using the correct National Insurance number
and deducting the right rate of
National Insurance contributions.
By law you are required to tell
HM Revenue & Customs about any income that is not fully taxed, even if you are not sent a tax return.
– HM Revenue & Customs