Belgium has fixed cameras, section controls (average speed) and mobile checks. Understanding how the figure on your fine is reached helps you judge whether to question it.
The technical margin
The measured speed isn't used raw. A tolerance is deducted in your favour before the fine is calculated — typically 6 km/h up to 100 km/h, and a percentage above that. The "retained" speed on your notice is already after this deduction.
How the fine scales
Small overshoots get a fixed settlement that rises with each extra km/h. Large excesses, or speeding in a zone 30 or near schools, escalate faster and can mean a summons rather than a simple settlement.
When to question it
- The vehicle in the photo isn't yours, or the plate is misread.
- You weren't the driver (you can declare who was).
- Signage or the zone limit is genuinely unclear.
- A calibration or device error you can point to.
For a borderline case a written explanation to the prosecutor can help; for a possible ban, talk to a lawyer. Quitte flags penal speed fines as higher-risk and won't pretend they're a sure win.