GuideStar provides JustGive's comprehensive database of more than 1.8 million public charities, making it easy for donors to find detailed information about charities that match their interests. GuideStar is an initiative of Philanthropic Research, Inc., a 501(c)(3) public charity founded in 1994. Their mission is to revolutionize philanthropy and provide information that helps users make better giving decisions.
JustGive uses the same nonprofit database that is maintained by Guidestar. If your organization is already listed in Guidestar (which is pretty much any 501(c)(3) organization), you are likely already in the JustGive database as well.