Rev. Rul. 58-66

The marital status of individuals as determined under state law is recognized in the administration of the Federal income tax laws. Therefore, if applicable state law recognizes common-law marriages, the status of individuals living in such relationship that the state would treat them as husband and wife is, for Federal income tax purposes, that of husband and wife.

The foregoing position of the Internal Revenue Service with respect to a common-law marriage is equally applicable in the case of taxpayers who enter into a common-law marriage in a state which recognizes such relationship and who later move into a state in which a ceremony is required to initiate the marital relationship. Accordingly, a taxpayer who enters into a common-law marriage in a state which recognizes such marriages is entitled, under the provisions of section 151(b) of the Internal Revenue Code of 1954, to an exemption of $600 for his common-law wife in making a separate income tax return, provided that, for the calendar year in which the taxable year of the taxpayer begins, she has no gross income and is not the dependent of another taxpayer. Also, for the purpose of filing a joint income tax return under section 6013(a) of the Code, a common-law wife in a state which recognizes such marriages will be considered to be the taxpayer's spouse.