Certification of Zero Income is an official document, issued by an appropriate government agency or other entity, that states that an individual or family has no income. It is typically used by those who are unemployed, retired, disabled, or otherwise unable to work to demonstrate to lenders, credit agencies, or other third parties that they are unable to support themselves financially. There are two main types of Certification of Zero Income: one for individuals and one for households. The individual version is usually used to prove that the applicant has no income from any sources, such as wages, investments, or government benefits, while the household version is used to show that the total household income is below a certain threshold.