snow_ski said:
I got the same question! I went to Canada long back (1998) so I have visitor visa. Where can I find my UCI?? :S
Where can I find my client ID/UCI?
This eight digit number appears on all documents you get from Citizenship and Immigration Canada (CIC). It looks like this: 0000-0000.
If you applied to CIC before
Look for this number on:
letters you received from CIC,
your immigration document such as a PR card, study or work permit.
If you do not have any of these documents but want to fill out an application form:
you can leave the field for UCI (Client ID) blank.
Note: If you have not dealt with CIC since 1973, you will not have a UCI or a Client ID.
http://www.cic.gc.ca/english/helpcentre/answer.asp?q=772&t=4