The Act was largely the result of a bipartisan ideological commitment to "a definition of citizenship including Britons and colonial subjects under the same nationality" and at a time "before large-scale migration was considered possible".

The resulting legislation passed by the United Kingdom for itself and its colonies was the British Nationality Act 1948, which was introduced by a Labour government.

It marked the first time that married British women gained independent nationality, regardless of the citizenship of their spouses.

Despite the fact that the Channel Islands and the Isle of Man were neither part of the United Kingdom proper nor were colonies of it, article 33 of the Act provides that when the Act mentions colonies, it must be construed as including references to these Islands.

The only significant provision of the Act to survive today is section 3, which concerns the extra-territorial jurisdiction of the criminal courts over crimes committed by British subjects overseas.

Section 3 restricted the scope of this jurisdiction to CUKCs (except in respect of crimes that would be against UK law even if committed by aliens).