CU (Glossary) (cross-border guide)
CU – Single Certification — Italian tax document certifying income received and withholdings during the year. Issued by the Italian employer.
By Frontaliere Ticino Editorial Team
In short
Example: If you only have Swiss income, no CU is issued; you use the Lohnausweis for your return.
On Italian documents the term reads «CU – Certificazione Unica»: Documento fiscale italiano che attesta i redditi percepiti e le ritenute subite nell'anno. Rilasciato dal datore di lavoro italiano.
The same concept in the site's other languages: German «CU – Einheitliche Bescheinigung», French «CU – Certification Unique».
The glossary provides clear, contextualised definitions of technical terms every cross-border worker encounters: fiscal acronyms (AVS, LPP, LAMal, IRPEF, INPS), administrative documents (CU, Modello 730, Lohnausweis, U1 Form), and legal concepts (fiscal domicile, permanent establishment, quasi-resident, concurrent taxation).
Each entry is written in accessible language and linked to the site's tools that use that concept. For example, from the definition of "withholding tax" you can access the payslip simulator directly, and from the "LPP" entry the pension calculator. This approach transforms the glossary from a simple dictionary into a practical navigation hub.
Understanding these terms is crucial for reading Swiss payslips, Italian tax declarations, official communications from the Ticino tax division, and letters from the Italian Revenue Agency. Bilingual terminology (Italian-German and Italian-French) also helps with direct communications to Swiss authorities.
The glossary also covers terminological differences between the Swiss and Italian systems: for example, "contributi sociali" in Italy corresponds to "Sozialabzüge" in Switzerland; "certificazione unica" (CU) is the Italian equivalent of the Swiss "Lohnausweis"; and "pensione di vecchiaia INPS" has its counterpart in the Swiss first-pillar AVS/AHV. These correspondences prevent confusion in cross-border documents.
Entries are regularly updated based on legislative changes, cantonal regulation amendments, and the most frequent questions from the cross-border worker community. Each term includes references to official regulatory sources (federal laws, bilateral agreements, AFC circulars) to enable independent further research.