Public servants will have to use two weeks' leave from their allowance to cover time spent in quarantine if they holiday abroad.
New rules say those embarking on non-essential travel abroad "must make provision by way of an annual leave or unpaid leave application for the additional period of restricted movement".
A Department of Expenditure and Public Reform spokesperson said working from home will not be acc- epted in lieu of leave.
The rules were added to a document on working arrangements in the public service during Covid-19.
It said authorities advise against non-essential travel overseas until further notice. This means anyone coming into Ireland, except from Northern Ireland, must restrict their movements for 14 days.
"This includes Great Britain but does not apply to Northern Ireland," the rules state.
A department spokesperson said it requires all public service employees to provide for a 14-day restricted movement period through additional leave.
"Throughout the Covid-19 pandemic we have operated as a unified public service," the spoksperson said.
"This requirement will apply to all public service employees to ensure equity of treatment between those who, due to the nature of their work, have been able to work from home during the crisis and those who have continuously attended the workplace throughout.
"If an employee chooses to go abroad for non-essential travel, they are going against government advice and essentially making themselves unavailable.
"While employees may have been at home to date, working from home is not a right of employment."