Some remarks, as I live here * Belgium used to have a bike tax, with license plates. I think it was abolished in 1991 when it was clear that the cost was high

Some remarks, as I live here * Belgium used to have a bike tax, with license plates. I think it was abolished in 1991 when it was clear that the cost was higher than what it was making. * The current engraving system engraved your national ID number in your bike, making it hard to sell your bike and causing privacy problems. The register would fix it * A lot of bikes are stolen for 1 ride, then left behind, mostly in one of the big parking lots at e.g. the railway station. The current registration is mainly usefull when big bike parkings get their yearly cleaning: Found bikes with a registration are returned to the owner. Of course, different cities do hugely different amounts of work, varying from none to a lot.