Victoria met Dr. Mitch Besser, the founder of mothers2mothers (m2m), in February this year following an invitation from Anna Wintour and American Vogue.
The money raised from the sale will be used to support mothers living with HIV in sub-Saharan Africa, educate them on how to prevent the transmission of the disease and improve the health of women and their families.
"It really was a life-changing experience; I've never experienced anything like it," Victoria said.
"I laughed a lot when we were going through my wardrobe as the pieces hold so many happy memories for me, David and the children. A lot of the clothes have been specially designed for me by the most talented designers and I've loved wearing them, however I now feel it's someone else's turn to enjoy them.
"We approached The Outnet, part of the Net-a-Porter Group, as they have an incredible global reputation and are the perfect partner for us to build awareness and raise as much money as possible for mothers2mothers".
So, how do you get your hands on Victoria's hats, shoes, bags and jewellery, designer ready-to-wear, costume pieces, coats, skiwear and evening dresses? All you need to do is register on The Outnet from 5 August for a chance to shop the collection.
An auction of 10 of the most iconic pieces from Victoria's wardrobe will be put up for sale in a 'Going, Going, Gone' reverse auction, where the starting price reduces by a fixed amount every five minutes.
LOVE VICTORIA'S IMMACULATE STYLE? Take a look through this gallery to see some of her greatest sartorial moments.
MORE! Watch all the latest on la Beckham right here.