What it is and where it is documented
Minimum necessary income is the income level a super visa host in Canada — the child or grandchild inviting a parent or grandparent — must meet or exceed for the application to qualify. It is documented in the letter of invitation, which IRCC says must include “proof that they meet or exceed the minimum necessary income.”
The threshold scales with household size, so the letter must also list “the list and number of people included when your child or grandchild calculated their family size to determine the minimum necessary income.”
Co-signing, and where the dollar figure comes from
A spouse or common-law partner who is “a Canadian citizen, permanent resident of Canada or registered Indian” may co-sign to help meet it; other relatives such as siblings cannot.
The specific dollar amounts are published separately by IRCC and change over time, so applicants should read the current figure from IRCC directly rather than from a third-party page.