Belgian NIS code
The five-digit code identifying a Belgian region, province, arrondissement or municipality in the classification kept by Statbel.
Statbel, the federal statistics office, maintains the NIS code, also published as REFNIS. One five-digit namespace covers every tier, and the tier is told by the trailing zeros rather than by a separate field.
Statbel describes the code as a province digit, an arrondissement digit and three digits for the municipality within that arrondissement. In practice that means a municipality has a non-zero final block, as Aalst does at 41002, while an arrondissement ends in 000, a province ends in 000 with a zero second digit, as Antwerp does at 10000, and a region begins with zero, as Brussels-Capital does at 04000.
The mergers of 2024 and 2025 cut Belgium from 581 municipalities to 565, and a merged municipality received a wholly new code rather than keeping one of the old ones: Tielt went from 37015 to 37022. Municipalities also moved between provinces.
The code is not a European NUTS code and cannot always be converted into one. The arrondissement of Verviers is a single NIS code that corresponds to two NUTS regions.
