Emergency contact detail on British passport

Hi all
I hope everyone is enjoying the hot summer before winter. But I have a question that is it mandatory to write down the emergency contact detail or next of kin on the last pages of British passport where it's asking that? If it's not written there then whether the visa officer in airport seize/stop entry into UK or penalized the person? How important is to write that? I am sure this question serve many.

Optional.

So it can be left blank? But if the holder wishes to write then can he give details of overseas person?

It can be left blank if you wish. You can write whoever yu want as a contact. The choice is yours. There is no penalty or anything if not completed.

The importance of listing someone is that the British authorities anywhere in the world know who to contact if you are traveling and something happens to you.

I have it blank in my passport, crossed border several times on it, nobody is looking there.

boloney wrote:I have it blank in my passport, crossed border several times on it, nobody is looking there.

There's no need for it.
After all its your own funeral.