You have confirmed that you received the NIP within 14 days, but that some or all of the details were inaccurate.You should correctly complete the notice providing the name and address of the driver at the time of the offence.  Even if the Notice was defective it will not always afford a defence to the offence of failing to supply information so you should always provide details and examine whether the defective notice provides a defence to the actual offence itself.

It is imperative that if you were the driver that you provide your details even if the NIP is defective and also if you consider that you are not guilty of the offence.  The defence to the substantive offence can be dealt with post charge/summons.  You must never fill in the form for some else named on the NIP and you must never write or allow someone else to complete it in their name if you were the driver.  This could lead a more serious charge which could result in imprisonment.