Why the years don't match
People often ask why a page like 1000 Lausanne 25 shows demographic data from 2024 right next to tax data from 2026. At first glance, it looks like we forgot to update half the page.
The truth is much more boring: official Swiss institutions just release their data at completely different times of the year.
For instance, our current metadata snapshot (from April 2026) pulls geometry from swisstopo 2026, tax data from ESTV 2026, but the official population count from 2024. This happens because the Federal Statistical Office (BFS) takes longer to finalize demographic numbers. The most useful way to read our pages isn't expecting one master year, but rather trusting that each block shows the latest official cycle available.
How we actually update the site
Behind the scenes, we run a sync script that checks each source against the current calendar year. If the federal API shows a newer year than what we have saved, we fetch the new dataset.
We don't treat all sources exactly the same. The BFS data has to pass our quality checks first before we write it to our database. Because the tax data (ESTV) relies on BFS numbers, a BFS update usually triggers a tax data refresh immediately after. We track all these update timestamps in our open metadata file so you can always verify exactly when we last pulled from Bern.
The best way to use this
Pay more attention to the source line under each data block than to the year in your calendar. If you're comparing 1000 Lausanne 25 and 8001 Zurich, the numbers are perfectly comparable as long as they both use the same demographic release year.
For quick comparisons and shortlisting places to live, PLZHub is generally all you need. But I always tell people: once your decision involves real money—like setting your budget based on local taxes or signing a lease—you have to double-check with the official cantonal tax calculator or local commune. We help you narrow down your choices, but we don't replace the final official check.
