Domestic partner benefits are benefits that an employer voluntarily chooses to offer to an employee's unmarried partner, whether of the same or opposite sex. An employer wishing to implement a domestic partner program needs first to identify what constitutes a domestic partner. The partners must be financially interdependent. Documentation of proof of a domestic partner relationship can take many forms. It is up to the employer to determine what is appropriate.
Some employers are satisfied with the partners signing a written statement of their relationship.
Some employers may require proof of some financial relationship, such as a joint lease or mortgage or copies of tax returns showing a financial interdependence. Whatever documentation is required must be germane to the issue of validating a domestic partnership, or it could lead to claims of invasion of privacy. However, most public attention involving domestic partner benefits involves employers that offer health insurance coverage to domestic partners. Eleven percent of workers worked in a firm that offered domestic partner coverage to same-sex couples and 12 percent of workers worked in firms that offered coverage to unmarried heterosexual couples. Many employers have a formal policy against discrimination on the basis of sexual orientation.