The NIF that you will receive through Novomove is permanent and it has no expiration date.
It is a unique 9-digit number that is assigned to you for life!
You may have noticed an expiration date in the upper right hand corner of your NIF document.
You can simply disregard this date because the Portuguese tax office has made the PDF document permanently acceptable as proof of your NIF.
The document that you have received has no expiration date and your NIF is permanent.