Written with people moving from Turkey in mind. The Portuguese rules still apply more broadly.
Do Children Need a NIF?
Yes, children need a NIF to enroll in school and for you to deduct their health and education expenses on your IRS tax return. Without it, you lose significant tax benefits.
You can request a NIF for a child at any Loja de Cidadão. You will need the child's birth certificate and your own identification. It is free and issued immediately.