Answer
For standard permanent residency, applicants must demonstrate a regular income sufficient to support themselves and their families. Older guidelines cite figures of around US$600–700 per person, but these should not be regarded as a fixed rule.
What matters to the migration service is not only the amount, but also the stability of the income: salary, pension, payment for services, rent, interest, or other lawful income. The documentation should show where the money comes from, how regularly it is received, and who it belongs to. A simple bank balance is usually insufficient because it does not demonstrate future income.
The amount should be assessed taking into account family composition, rent, and the actual budget. For a family with children, the formal minimum may appear less convincing than an income that covers ordinary expenses. Therefore, before applying, it is better to obtain an up-to-date guideline for the specific grounds and prepare the documents accordingly.