Source of all law is the constitution or “Basic Statute” (Grund-gesetz)

The ultimate source of all law is the constitution or “Basic Statute” (Grund-
gesetz). Acts of either the federal or a provincial parliament are void if they
conflict with the constitution or are passed in an unconstitutional manner.
Similarly, all acts of the provincial parliaments must be in accordance with the
provisions of the constitution of the relevant province.

The government, individual ministries and other authorities have the power to
issue guidelines, decrees and other pronouncements. These ordinances are of
varying degrees of authority and require the approval of differing levels of
government. Tax guidelines, for example, but not decrees, require the consent
of the Bundesrat. These extra-statutory instruments bind, at least to the extent
of their own terms, the issuing authority and its subordinate authorities, but not
courts of law. They cannot amend the law as it stands, but give guidance on the
issuing authority’s preferred interpretation thereof.