Which insurance policies are compulsory in the Netherlands?

In law, two: health insurance for anyone who lives in the Netherlands or pays wage tax here, and third-party liability insurance for every motor vehicle registered in your name. Anyone who names a third almost always means buildings insurance (opstalverzekering). That is not in the law, but in the mortgage conditions of almost every lender.

The CAK traces people who are required to be insured but are not and first sends a reminder to take out insurance yourself. If that does not happen, an administrative fine follows and ultimately automatic cover whose premium is deducted from your income. Healthcare costs you incurred during the uninsured period remain at your own expense.

No. There is no law requiring a homeowner to insure their home. In reality almost every mortgage lender does require it, because the home is the security. With a flat the buildings cover usually runs through the VvE's joint policy, whose basis is the regulations under Article 5:112 of the Dutch Civil Code.

For private individuals, no. The AVP is voluntary, while your liability under Article 6:162 of the Dutch Civil Code simply exists and can run high with personal injury. For some professions the position is different: financial advisers, lawyers and civil-law notaries do have to hold professional indemnity insurance under legislation or professional rules.