Anyone in the household who qualifies can claim the Northern Residents Deduction on their tax return. However, in some cases it may be more advantageous for only one person in the household to take the Northern Residents Deduction. If only a single person takes it, they can also get an Additional residency amount which may be worth more than if everyone takes it.

More information on the Northern Residents Deduction from the CRA:

https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-re...