An Acknowledgment of Receipt (AOR) is an official letter that IRCC sends you confirming they have received your application and will start processing it. Receipt Number; A-Number (if applicable); Date when filed; Application or Petition filed; Item not received; Email Address.If we start processing your application, we'll send you an acknowledgement of receipt letter or email with an application number. Employers and employees must complete their respective sections of Form I9. The form is used to document verification. Discover the value of acknowledgment letters in confirming the receipt of deliveries. Use our free template to craft an effective, professional letter. PERS will mail additional forms necessary for completing the service retirement application after receipt of the completed Form 9A SRVC. Create a passcode for this ticket to view information and responses. Passcodes must be a minimum of 15 characters and contain at least one lowercase letter.