The Cook Islands Chamber of Commerce says there are still some issues which need to be resolved with the National Superannuation Fund before it's extended to cover the private sector.
The chamber president, Teresa Manarangi Trott, says some employers will find the levy too costly on their wages bill so they need to negotiate the level at which they enter.
It's anticipated that employers will add approximately three per cent to their wages bill by joining the scheme.
Ms Manarangi Trott says it will also be difficult for those who are self-employed.
"The major problem, I think, in implementing the fund is for those people who are self employed - for example, growers, who then sell informally at the market. Their income isn't regular so they're going to have problems identifying those people and establishing how their contributions are going to be made to the fund."
The chief executive of the National Superannuation Fund, Taukea Raui, says the Act makes it compulsory for all workers to join but some private companies with their own funds may be exempt.