eBay for Charity is working with the Association of Charity Shops to help charities make the most of its online fundraising service.
The two organisations will hold an event on online fundraising for association members in May as part of a new six-month collaboration between the bodies.
eBay for Charity was launched in November last year for Children in Need.
More than 350 charities have signed up, from large bodies such as the RNLI, Oxfam and Cancer Research UK, to small community organisations.
Charities wanting to sell goods on the site have to register with MissionFish, a charity specialising in online trading for charities. Individuals can also sell items and donate part or all of the final sale price. All items sold on the site are also listed on the main eBay auction site.
The event in May will discuss how charities can use the internet to sell items and fundraise through the site. The association will send members a newsletter with further information.
Lekha Klouda, executive secretary of the Association of Charity Shops, said working with eBay would be a "mutually beneficial" exercise that would give her members access to eBay's expertise.
Sharath Jeevan, head of eBay for Charity, said eBay had a large community of users and the tie-up would give charities greater knowledge of its services.