You can create a Cook Island Tax Certificate from Payroll, Reports, Other Reports Cook Island Tax Certificate. These are normally printed at the end of the financial year after all transactions have been completed.
The status for the report is recorded on the in the Tax Certificate Status field within the Employee Masterfile (Payroll, Masterfiles, Employee Details, Maintain/Enquire, Tax tab). This is available when the Country field from Setups, Payroll, Options Payroll Options, Options tab, Payroll Configuration task area is set to Tonga, Fiji, Solomon Islands or Samoa.
Once this has been created and/or printed, then you are unable to process a further pay for the employee. You will not be able to check a pay, and it will be rejected in the Check Pays process.
The only solution to be able to proceed with paying the employee is to Restore an Archive from before the Tax Certificate was created or setup a new Employee Masterfile for the employee. There is no 'Delete' option unfortunately.