The result must be consistent with the Constitution: The modified legislation, after reading-in or severance, must fully comply with the Bill of Rights and other constitutional provisions.

Here are the requirements laid down in National Coalition for Gay and Lesbian Equality v Minister of Home Affairs 2000 (2) SA 1 (CC) before reading-in or severance could take place:

• The result must be consistent with the Constitution: The modified legislation, after reading-in or severance, must fully comply with the Bill of Rights and other constitutional provisions.
• The alteration must be as minimal as possible: The court should make the least intrusive changes necessary to remedy the unconstitutionality, respecting the legislative intent as much as possible.
• The meaning and purpose of the statute must remain substantially the same: The core objective and overall scheme of the legislation should not be fundamentally altered by the court's intervention.
• The court must be able to define with sufficient precision how the statute is to be modified: The court needs to be clear and specific about the exact wording to be added (reading-in) or removed (severance) to avoid ambiguity or further legal uncertainty.
• The court must be satisfied that the order will not have an undue impact on other provisions or on third parties: The remedy should not create new constitutional problems or unfairly prejudice individuals or groups not directly involved in the litigation.
• The court should not usurp the function of the legislature: While correcting unconstitutional provisions, the court must avoid overstepping its judicial role and effectively rewriting legislation, which is the prerogative of Parliament.