At the end of paragraph (3) of regulation 15 of the Maintenance Assessments and Special Cases Regulations (amount of housing costs) there shall be added—

• “but, where that other person does not make those payments in circumstances where head (a) of paragraph 4(2) of Schedule 3 applies, the eligible housing costs of that parent shall include the housing costs for which, because of that failure to pay, that parent is treated as responsible under that head.”.