Quick Question for visitor extension app

[hillaryh]

On the visitor extension app it is asking for a UCI number..

Since I am the applicant, the one being sponsored to come to canada, would I just enter "NA"

OR

Would this be the number attached to my SA Letter ( I had figured that UCI was attached to my husband, the sponsor.)

 

[lleahdoll]

Both the sponsor and principal applicant have a UCI #, however this spot is usually used if you have submitted an extension or anything else to CIC before. You can leave it blank if you don't know yours.