Employees should work from home from today unless it is necessary to attend the workplace in person.
The measures are among the latest Government restrictions being put in place to stem the spread of Covid-19.
Just two months after a gradual return to the workplace began, the situation is going into reverse.
Under the latest guidelines, unless it is necessary to attend the workplace in person, everyone should revert to working from home.
Those attending cinemas and theatres will need Covid-19 passes based on vaccination or recovery to be let in.
Closing times for licensed premises, including hotel bars and hotel residents' bars, will move to midnight.
All customers will need to have left the premises by that time, regardless of the event taking place, including weddings.
The latest restrictions were announced by the Government earlier this week in an effort to slow the spread of Covid-19.