The UIDG defines in Article 3 the terms related to the UID and also defines who qualifies as a UID entity and thus receives a UID. From a Liechtenstein perspective, the following should be highlighted 

• Liechtenstein-based legal entities with business establishments in Switzerland.
• Liechtenstein-based legal entities that need to be identified for the enforcement of Swiss law.
• Companies and persons (natural and legal) subject to Swiss agricultural, animal health, animal welfare or food legislation. This legislation is applicable in Liechtenstein due to the customs treaty with Switzerland.  

If you recognize your company in one or more of these groups, you are strongly advised to apply for a UID