Over 100 people have so far updated their work and residence permits with the Cook Islands Immigration Department since the one-month grace period was granted on November 1st.
Principal Immigration officer Tutai Toru says the response has been good but he feels there are more out there who haven't come in yet.
Mr Toru says they're receiving a lot of telephone calls from employers about requirements for their foreign employees.
He says it's likely any foreign workers found to be illegal residents after the grace period will be deported.
"Certainly we're quite happy at this but we didn't know it was that much - that there were people without paper works. But we are quite happy that people have taken steps to make sure that their workers have the right papers and the workers are now checking up with their employers whether they have the right permits. This is a good thing as this periods has given everybody a shake-up."
Principal Immigration Officer Tutai Toru