Car written off by Argos, Cat N, but I want to repair it

[Barnaby]

I was driving along and was hit by an Argos van. The damage is to the rear near side door. The car is a 2013 Kuga that I bought for £4.3 just over a year ago. mileage is 170k miles.

They have offered £3k - £500 scrap as they have declared it a Cat N. I have no choice but to accept their offer as I would need to get an engineer to dispute their evaluation.
I am considering repairing the car myself with a second hand door.
I am not sure what my legal duties are with regard to my notifying my insurance company of the Cat N designation and how to inform the DVLA.
I would be grateful if anybody could offer advice.
Thanks

[Pezza54]

The car will have a Cat N marker on the insurance database for the rest of its life. You cannot hide this from insurance companies and you should be honest on any application forms
Insurance for cat n cars is usually more expensive

Once repaired and roadworthy (mot) re-registration with DVLA is not necessary.