You became a British subject on 1 January 1983 if, until then, you were either:
a British subject without citizenship, which means you were a British subject on 31 December 1948 who did not become a citizen of the UK and Colonies, a Commonwealth country, Pakistan or the Republic of Ireland
a person who had been a citizen of the Republic of Ireland on 31 December 1948 and had made a claim to remain a British subject
You also became a British subject on 1 January 1983 if you were a woman who registered as a British subject on the basis of your marriage to a man in one of these categories.