Oxfam is applying to create a second shop in the city in East Street.
Number 36, between the Body Shop and the former Zest for Taste shop, would undergo minor structural alterations to design a new sales area on the ground floor and storage on the first floor.
A micro-lift would be installed to help bring goods from one floor to the other and a toilet area would be removed under the plans, submitted to Chichester District Council.
The charity has an existing shop in South Street.
See application reference 18/02201/FUL