Form CIT 0458 is the equivalent of form IMM 5409, but for applications processed under the Citizenship Act rather than the Immigration and Refugee Protection Act.
Two common-law partners formally attest to the nature and length of their relationship for a citizenship-related application. The signature must be taken before a person legally authorized to swear the document.
The oath, in brief
Form CIT 0458 contains a declaration under oath or a solemn declaration: it must be signed before a person legally authorized to receive it — a Commissioner for Oaths, notary, lawyer, or justice of the peace. Once sworn, the declaration has the same weight as a statement made before a court.
In Québec, a Commissioner for Oaths can administer this oath remotely, by videoconference, when the required conditions are met (seeing and hearing each other, viewing the document, keeping it confidential).
Where to get the form
Form CIT 0458 is published free of charge by IRCC (Immigration, Refugees and Citizenship Canada) on canada.ca.
Download form CIT 0458 (canada.ca)
Have form CIT 0458 sworn online
Form CIT 0458 is sworn online simply, with a Commissioner for Oaths available quickly for a signature that meets IRCC requirements.
Before booking, confirm with the receiving organization that an oath administered by a Québec commissioner meets the requirement, especially if your file is handled outside Québec.