A UCI (unique client identifier) is a client identification number that is assigned to an individual who interacts with Canadian immigration authorities. It is an eight or ten-digit number that is on all official documents that an individual receives from Immigration, Refugees and Citizenship Canada (IRCC). The UCI has either four numbers, a hyphen, and four more numbers (Example: 0000-0000) or two numbers, a hyphen, four numbers, a hyphen, and four more numbers (Example: 00-0000-0000). If an individual is applying to IRCC for the first time, they will not yet have a UCI. If a form asks for a UCI and an individual does not have one, they should write "Not Applicable" or "N/A" in the space provided. An individual can find their UCI on immigration documents such as their Permanent Resident Card, Landing Document/IMM1000/5292/5688, or Notice of Decision Letter.