According to the Postal Services Directive (PSD), EU member states must ensure that users enjoy the right to a universal service involving the permanent provision of a postal service of specified quality at all points in their territory at affordable prices for all. However, member states may define the details of the postal universal service obligation (USO) differently in their national laws and regulations.

The PSD further requires member states to ensure that the universal service provision evolves in response to the technical, economic and social environment and to the needs of users. A number of countries have taken steps to reconsider the scope and features of their postal USO in response to the continuous decline in letter volumes and changing communication behaviours.

Modifications to the USO at national level are typically made by regulatory decisions and/or amendments to relevant secondary legislation. More dramatic changes to the rules affecting the postal sector are introduced through revisions to primary legislation.