Prince Harry and Meghan Markle have asked for donations to charity, rather than wedding gifts, Kensington Palace said.
Kensington Palace said: "Prince Harry and Ms Markle do not have any formal relationships with the charities chosen.
"The couple have chosen charities which represent a range of issues that they are passionate about, including sport for social change, women's empowerment, conservation, the environment, homelessness, HIV and the Armed Forces. Many of these are small charities, and the couple are pleased to be able to amplify and shine a light on their work."
The palace said the couple has selected seven organisations: CHIVA (Children's HIV Association); Crisis; the Myna Mahila Foundation; Scotty's Little Soldiers - a charity for bereaved Armed Forces children; StreetGames; Surfers Against Sewage; and The Wilderness Foundation UK.
Crisis - the national charity for homeless people - welcomed being chosen by Harry and Ms Markle.
There has been a furore over the treatment of homeless people in Windsor, where the couple will marry on May 19, after Tory councillor Simon Dudley called on police to clear rough sleepers from the town before the high profile wedding.
Jon Sparkes, chief executive of Crisis, said: "We are hugely grateful that Prince Harry and Ms Markle are asking the public to support Crisis as they celebrate their wedding.
"Homelessness is one of the most urgent issues of our time, but at Crisis we know what it takes to end it.
"Donations will help us to support more people to leave homelessness behind through our housing, employment, education and advice services across the country, and to campaign for the changes needed to solve the homelessness crisis once and for all."
The prince and the American former actress also picked a charity that Ms Markle has visited in India.
The Myna Mahila Foundation empowers women in Mumbai's urban slums, by offering stable employment close to their homes, and breaking taboos around menstrual hygiene by offering women access to low cost sanitary pads, and accurate information.
Suits star Ms Markle wrote about the Foundation's work combating period poverty in Time Magazine last year, highlighting how the schooling of young women in India is disrupted when they are menstruating.
Suhani Jalota, who founded Myna Mahila in 2015, said: "This support will enable us to expand our reach into more urban slums in Mumbai, empowering local women through access to menstrual hygiene products and employment opportunities."