Do I have to do ONA?
You need ONA if you integrate under the 2013 Act or voluntarily, for example for naturalisation in the Netherlands. You do not need it under the 2021 Act, if you had to integrate before 1 January 2015, if you have a Dutch MBO level 1 diploma, or if you got an exemption because you worked in the Netherlands. For naturalisation, the IND also lists exemptions for people who registered with DUO before 1 January 2015 and paid before 1 February 2015, people who reached state pension age, and people who are fully unable to work.