Shotley Gate Stores will close its door for the final time on Sunday.
Owner Alison Smith has given the three part-time staff a week's notice.
Alison and her partner bought the property at the top of Bristol Hill two years ago from Barrie Powell who successfully ran it as a shop and Post Office for 22 years.
It is understood they now plan to apply for change of use and convert the building into a house.
The building has stood on the plot in one form or another since 1863 when it was first used as a sorting office, with the post brought by mail train to Harwich, ferried across the harbour to Shotley Gate and sorted before going off to Ipswich.
To try and lessen the impact, Sarah Pallant at the Shotley Rose will be selling fresh bread and rolls, including cheese rolls.
Manish Patel at the Shotley shop and post office in Kingsland is considering making deleiveries to Shotley Gate, while there is also a milk delivery service.
In the longer term, there are provisions within the Ganges development plan for a number of retail units, one of which is earmarked for a mini-supermarket.