The administrative directive dated Feb. 1 and issued by the Office of the Prime Minister says the aim is to promote efficiency and contain expenditure.
The directive comes a day after President Hage Geingob announced that he had suspended all trips outside the country by ministers, deputy ministers and all political office bearers with immediate effect until the end of February.
According to the directive, the government seeks to establish control systems that will reduce personnel and related expenses as well as reduce transport costs in the next three financial years.
With immediate effect, all air travel will be by long-haul flights, and that those travelling by road can only drive for more than 500 kilometers where there is no other option.
The number of those travelling outside the country has been limited to two people, and where there are more, then the Secretary to Cabinet has to be consulted.
The directive also limits travels outside the country to two trips per year and just three within the country although there will be exemptions.
All permanent secretaries, according to the directive, will have to seek permission to travel from the Secretary to Cabinet, who will then consult the minister before approving.
Furthermore, the directive bans any ministry from buying new vehicles with the Secretary to Cabinet's approval and restricts the use of government vehicles strictly to official use.
With immediate effect, the directive says, departmental meetings can be held via telephone or video conferencing to reduce travelling costs and lost production time.
The directive also encourages the use of email to reduce printing of letters, memorandum and photocopying and delivery of documents.
"Posts that remain vacant for more than six months should be abolished and may be given up for compensatory reductions," the directive says, adding that the Secretary to Cabinet will have to approve any new posts.
Also, the directive says supervisors will now have to approve overtime work that has to be done in the most cost-efficient manner.
Those who fail to comply, according to the directive, may face disciplinary action.