All Jersey workers now have the right to a minimum wage, holiday pay and protection against unfair dismissal. The island's first Employment Law means everybody is now entitled to be paid at least �5.08 an hour.
They can expect at least two weeks' paid holiday, as well as all bank holidays, and they should get at least one day off in a seven-day period.
The law also gives protection against unfair dismissal with the right to go to an employment tribunal.
Free handbook
Richard Plaster, chairman of Jersey's Employment Forum, said he believed only when tribunals were used would the full effect of the law become apparent.
He said: "When a tribunal has to make a decision on a case, it will be down to the quality of the chairman and the vice chairman and their members, and that will be an interesting one to watch."
Employers now have to provide a written job description and proper itemised pay slips to employees.
Temporary workers and those on short-term contracts have the same rights as full time staff.
The Jersey Advisory and Conciliation Service has been advising firms about the new laws and has published a free handbook.
The minimum wage for adults in the UK rises from �4.85 to �5.05 an hour in October.