To celebrate 100 years of service to the community, Australia's top designers are offering their wares to support the iconic shops that have become known and loved around Australia as "Vinnies".

Shoppers will get a chance to rummage for 100 hidden treasures sprinkled in Vinnies stores around NSW - with exclusive labels including Lee Mathews and Ellery among those on offer.

Other brands that have donated their wares for the iconic op shop include: Bassike, Furla, Jac + Jack, Jets, Kathmandu, Matteau, Mulberry x Acne Studios, Sarah-Jane Clarke, Seafolly and Shona Joy.

Customers who bag a bargain at Vinnies until November 6 also have the chance to win a vintage Chanel bag and a Delonghi coffee machine.

Vinnies NSW executive director Yolanda Saiz says designers and brands jumped at the chance to donate to the centenary campaign.

"It sends a really good message that these brands understand the value of Vinnies," she told AAP.

"When you go into Vinnies, you're going to find some great day-to-day items, but you're also going to find that treasure you wouldn't usually buy for yourself at a great price."

Vinnies will reopen its Newtown store in Sydney's inner west on Thursday evening, just down the road from the original store, to mark a century since its inception.

The first store was brought to life in 1922 by members as a waste collection depot.

"It was taking all sorts of things discarded from homes that people had no use for - furniture and items of clothing," she said.

Vinnies stores have evolved to play an important role in helping people, especially as inflation soars and people face more financial pressure.

"In NSW, one-in-four people who come to Vinnies are doing so for the first time as they struggle to keep up with the cost of living," Ms Saiz said.

"The fact that so many Australian individuals and families are struggling to put food on the table should be concerning to all of us."

Australian Associated Press