A supposedly Christian body is not referred to as denominational if it has only one congregation. It is referred to as an Independent, or an independent, if it has its own building to which anyone may make enquiry; a house group, if it meets in a home or homes, and membership is through personal contact only, though this is a minor distinction, and both types can be described as independents. Some independents get together to make a loose federation that gives them joint benefits, but they remain autonomous, unlike a congregation of a denomination, which is controlled by a central authority.
Many Christians have left denominations because they have been unable to influence those central authorities, which have become increasingly unsatisfactory to them.