BRP card in post

Hi,
By the grace of god, my T1 Ent extension have been granted.
I just received an email about it and it is said that it will need to be signed for on delivery.
I just wanted to know if im not available during the time the delivery arrives, will they accept identification from anyone and at the address or do i need to be present myself? can they (whoever is available at the time of delivery) show their own identity to receive or can they show my identity and receive it?


also it was mentioned that i need to send back the old brp card?
thanks.