13.—(1) A marriage celebrated after the commencement of this Article shall be void on the following grounds only, that is to say—
(a)that the parties are within the prohibited degrees of relationship;
(b)that it is not a valid marriage under the provisions of the Age of Marriage Act (Northern Ireland) 1951 [1951 c.25] (persons under 16);
(c)that it is not a valid marriage by reason of non-compliance with any statutory provision or rule of law governing the formation of marriage;
(d)that at the time of the marriage either party was already lawfully married[F1 or a civil partner];
F2(e). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(f)in the case of a polygamous marriage entered into outside Northern Ireland, that either party was at the time of the marriage domiciled in Northern Ireland.
(2) For the purposes of paragraph (1)( f) a marriage[F3 is not polygamous if] at its inception neither party has any spouse additional to the other.
[F4(3) Paragraph (4) applies in the case of a marriage which results from the conversion, or purported conversion, of a civil partnership into a marriage—
(a)under Part 3 of the Marriage and Civil Partnership (Northern Ireland) (No. 2) Regulations 2020, or
(b)under Part 3 or 4 of the Marriage of Same Sex Couples (Conversion of Civil Partnership) Regulations 2014 where the civil partnership is a convertible Northern Ireland civil partnership as defined by regulation 2 of those Regulations.
(4) The marriage is void if (but only if) the civil partnership was void.]
F2Art. 13(1)(e) omitted (13.1.2020) by virtue of The Marriage (Same-sex Couples) and Civil Partnership (Opposite-sex Couples) (Northern Ireland) Regulations 2019 (S.I. 2019/1514), regs. 1(2), 5(1) (with regs. 6-9)