http://www.legislation.gov.uk/ukpga/2002/21/notes/paragraph/43Tax creditsBenefits for parents and childrenBenefitsIncome supportChild benefitExplanatory Notes to Tax Credits Act 2002Inland RevenueKing's Printer of Acts of Parliament2014-07-03 21 8 July 2002 43 Claims may be made jointly by married or unmarried couples, or by individuals who would not be entitled to make a claim as part of a couple (subsection (3)). Entitlement to a tax credit comes to an end if a couple who have made a joint claim stop being entitled to make such a claim (that is, they separate) or an individual who has made a single claim becomes part of a couple and stops being entitled to make a single claim (subsection (4)). For the purposes of this Part, the definition of “married couple” follows that used for income tax and means any married couple in which the partners are neither formally separated nor separated and likely to remain so permanently (subsection (5)). An “unmarried couple” is defined as a man and a woman living together as husband and wife (subsection (6)). Individual claimants make a “single claim”, and couples make a “joint claim” for tax credits.