(1)This section applies—
(a)to any individual who is not entitled for the year of assessment to the higher (married persons) relief under section 257(1); and
(b)to any married man who is entitled for the year of assessment to that higher relief but whose wife was throughout that year totally incapacitated by physical or mental infirmity.
(2)Subject to subsections (3) and (4) below and to section 260, if the claimant, being a person to whom this section applies, proves in the case of a year of assessment that a qualifying child is resident with him for the whole or part of the year, he shall be entitled to a deduction from his total income of an amount equal to the difference between the higher (married persons) relief and the lower (single persons) relief under subsection (1) of section 257 as it applies to persons not falling within subsection (2) or (3) of that section.
(3)A claimant is entitled to only one deduction under subsection (2) above for any year of assessment irrespective of the number of qualifying children resident with him in that year.
(4)A person to whom this section applies by virtue of subsection (1)(a) above shall not be entitled to relief under this section for a year of assessment during any part of which that person is married and living with his or her spouse unless the child in connection with whom the relief is claimed is resident with that person during a part of the year in which that person is not married and living with his or her spouse.
(5)For the purposes of this section a qualifying child means, in relation to any claimant and any year of assessment, a child who—
(a)is born in, or is under the age of 16 years at the commencement of, the year or, being over that age at the commencement of that year, is receiving full-time instruction at any university, college, school or other educational establishment; and
(b)is a child of the claimant or, not being such a child, is born in, or is under the age of 18 years at the commencement of, the year and maintained for the whole or part of that year by the claimant at his own expense.
(6)In subsection (5)(a) above the reference to a child receiving full-time instruction at an educational establishment includes a reference to a child undergoing training by any person (“the employer”) for any trade, profession or vocation in such circumstances that the child is required to devote the whole of his time to the training for a period of not less than two years.
For the purposes of a claim in connection with a child undergoing training, the inspector may require the employer to furnish particulars with respect to the training of the child in such form as may be prescribed by the Board.
(7)If any question arises under this section whether a child is receiving full-time instruction at an educational establishment, the Board may consult the Secretary of State or the Department of Education for Northern Ireland.
(8)In subsection (5)(b) above the reference to a child of the claimant includes a reference to a stepchild of his, an illegitimate child of his if he has married the other parent after the child’s birth and an adopted child of his if the child was under the age of 18 years when he was adopted.
(9)Notwithstanding anything in section 9 of the [1969 c. 46.] Family Law Reform Act 1969 or section 5 of the [1969 c. 28 (N.I.).] Age of Majority Act (Northern Ireland) 1969 or any rule of law in Scotland, for the purposes of subsection (5) above a child whose birthday falls on 6th April shall be taken to be over the age of 16 at the commencement of the year which begins with his 16th birthday and over the age of 18 at the commencement of the year which begins with his 18th birthday.