+1(514) 937-9445 or Toll-free (Canada & US) +1 (888) 947-9445
You will get your UCI in your AOR1 (acknowledgement of receipt). This comes after IRCC has briefly looked through your application and determined it is 'compete' (no missing signatures, all required forms, etc. Though they may will ask you for additional paperwork later on. AOR1 come anywhere between 4-8 weeks after you've submitted your application. If you provided and email address in your application, it will be sent there.