As per The Pensions Regulator, an employee can only be postponed for up to three months. If your pension scheme operates on a Team Assessment basis, and you don't want your employee to start contributing to the pension after their postponement period, you can exclude them from the pension.
This will remove the employee from the pension and they will not be automatically assessed by the system and enrolled into the pension if they meet the auto enrolment criteria.
Excluding employees from pension:
Go to the Company.
Go into Pensions.
Go into the pension scheme .
Go to the Team tab.
Locate the employee you want to exclude.
Click on the actions cog for the employee and select Pension status.
Tick the box Exclude (employee's name) from all AE pensions.
Save.
Once the employee is excluded the system will not enroll them automatically and it will be the admin's responsibility to then add the employee back into the pension and select the right pension status for them.