Checklist: paperwork to sort out before your first inburgering exam

I am doing inburgering voluntarily (EU citizen, so no obligation), and before my first exam I discovered that the paperwork takes longer than the studying. This is the list I wish someone had given me.

1. BSN first. You get it when you register at your municipality (BRP). Everything below depends on it.
2. DigiD. Apply at https://www.digid.nl — you need a BSN and to be registered at your address. The activation code comes by post within a few working days. Without DigiD you cannot use Mijn Inburgering, where you book exams.
3. Valid ID. Check the expiry date today, not the night before. A passport, EU ID card or Dutch residence document all work. An expired or damaged document means no exam, and you have to register again.
4. Money. Under the 2021 rules each exam part costs €50 — Reading, Listening, Writing, Speaking and KNM, so €250 if you take all five. You pay online when you book. Asylum status holders get the first 2 attempts of each exam free, so check https://www.inburgeren.nl for your own situation.
5. Time. It can take more than 6 weeks before you can actually sit an exam. You can still change or cancel up to 1 week before and get the money back.
6. Keep the DUO letters. The invitation arrives about 1 week before the exam and contains the main rules.

Nothing here is difficult. It is just six small queues, and each one starts earlier than you think.