Free movement
EEA free movement: no work permit needed (quotas apply)
Free movement of workers applies in general terms to Iceland, Liechtenstein and Norway as part of the European Economic Area, so EU and EEA citizens can generally work without a work permit. Liechtenstein, however, limits the number of people who can work and live there through quotas.
Source: European Commission – Free movement of EU nationals (employment-social-affairs.ec.europa.eu).
What the source says
"work there without needing a work permit" … "Free movement of workers also applies, in general terms, to the countries in the European Economic Area (Iceland, Liechtenstein and Norway)." … "Liechtenstein imposes quotas that limit the number of people who can work and live there." (https://employment-social-affairs.ec.europa.eu/policies-and-activities/moving-working-europe/working-another-eu-country/non-eu-nationals_en)