An Acknowledgment of Receipt (AOR) is an official letter that IRCC sends you confirming they have received your application and will start processing it. Aor is an official letter that the ircc sends you confirming they have received your application and will start processing it.If we start processing your application, we'll send you an acknowledgement of receipt letter or email with an application number. On this, the ____ day of ______, 20____, before me. (notary), the undersigned officer, personally appeared.