Northern Ireland will become the first part of the UK to criminalise paid-for-sex.
Those who break the law will face up to one year in prison.
The Northern Ireland Assembly has passed the Human Trafficking and Sexual Services Bill, which includes criminalising the purchase of sex.
Prostitution is currently legal in the UK and most EU countries, while many aspects of the trade, including brothels and public solicitation, are illegal.
The move in Northern Ireland echoes laws already in place in Scandinavian countries that opts to make customers guilty of crimes, rather than the prostitutes.
The Republic of Ireland is considering similar laws.