One of a Kind Gunnedah's last trading day will be Monday, November 25.
The store's staff announced via Facebook that all items were on sale in preparation for the closure.
Ladies and men's clothing are $2 each, children's clothes are 50c each, shoes are $1 a pair, and bric-a-brac is heavily discounted.
The store will be open for its regular hours in the next week except Saturday, November 23, when the store will be closed.
Retail manager Jenny Watterson thanked everyone who supported the store.
"It is with a heavy heart I would like to sincerely thank our loyal customers and donors," she wrote.
"A massive thank you to those who have supported us."
The closure came after the charity association appointed administrator Andrew Barnden because of concerns that "cash inflows [weren't] sufficient to cover future outflows".
The Namoi Valley Independent contacted Mr Barnden for an update on the future of the company but received no response.
The Tamworth store will remain open, but all others will close, including Narrabri, Armidale and Toowoomba.