Do I need to send the 'working sheet' page or P11 to HM Revenue & Customs?

HMRC do not require you to send them this form, they only ask you to keep a form P11 or an equivalent, for your records. The Working Sheet page of our system is an equivalent, so you do not need to fill out a separate form P11.

Form P11 should not be confused with form P11D, which is used for a totally different purpose.