A new Post Office counter will open in an Old Town convenience store to replace the service closing at Butlers Emporium.
From September 1, Premier Stores, George Street, will start offering services such as pension and benefit withdrawals, electronic bill payments and sending mail.
These will be available between 7am and 10pm Monday to Friday and from 8am to 10pm on Saturday and Sunday.
The existing Post Office at Butlers Emproium, also in George Street, will continue operating until the end of September.
Premier Stores manager Rashmi Amin said: "The services are going to be limited but I think it will be useful for cutomers and bring extra people into the shop."
The move has been welcomed by campaigners fighting to keep a Post Office in the Old Town including Hastings MP Michael Foster who said: "Customers will have a more streamlined service with over 90 per cent of the transactions provided by the former Post Office, and for longer opening hours.
"It is good that the Post Office have listened to the needs of local residents and, indeed, to the many visitors to this part of town."