It used to be 10 years but was reduced to 8 a few years ago. You keep the 30% rule after you apply for citizenship though. It even applies to native residents

It used to be 10 years but was reduced to 8 a few years ago. You keep the 30% rule after you apply for citizenship though. It even applies to native residents who haven't lived in NL for more than 10 or 20 years.