Objecting to your WOZ valuation
What to know before you file: the deadline, the legal requirements, and which grounds work.
You have six weeks
The clock starts on the dagtekening printed on your WOZ decision: the date on the letter, not the date you received it. Your objection must reach the municipality within six weeks. If you post it on the last day it still counts when it arrives within a week after the deadline (article 6:9 Awb), but that is a risk you do not need to take.
What your objection must contain
Dutch law (article 6:5 Awb) sets five requirements: your name and address, the date, a description of the decision you are objecting to (the assessment number and its dagtekening), the grounds for your objection, and your signature. Miss one and the municipality can declare the objection inadmissible without looking at the substance at all. Woonbelasting checks this before it gives you the PDF.
Always request the valuation report
Under article 40 of the Wet WOZ the municipality must give you the valuation report for your home, including the reference properties it used itself. That report often shows exactly where things went wrong: a floor area that is off, a dormer that does not exist, or reference homes finished to a far higher standard than yours. The request is included in every Woonbelasting letter by default.
Which grounds work best
A factual error is strongest: if the floor area, build year or extension is wrong, that has to be corrected; it is not a matter of opinion. Next come the value-reducing circumstances the municipality cannot see: deferred maintenance, a kitchen from 1985, foundation problems, noise, leasehold. The comparison with your neighbours is good supporting evidence, but rarely enough on its own.
What a successful objection is worth
A lower WOZ value reduces your property tax (OZB) and, depending on your situation, the notional rental value in your income tax return, the water authority levy, and inheritance tax on an inherited property. Tenants in regulated housing can use a lower WOZ value against the maximum rent. Objecting is free, even if you lose.
The risk you should know about
The municipality can re-assess your home. In practice the value is rarely raised on objection, but it can happen. If your home is already valued below comparable homes on your street, Woonbelasting advises against objecting, and says so.