Acquisitions of Swiss citizenship by former nationality and crude naturalisation rate
bfs-naturalisations
- Publisher
- OFS/BFS
- Access method
api- Table id
su-d-01.05.06.01.01 + su-d-01.05.06.01.08- Licence
- BFS terms of use OPEN-BY: "Open use. Must provide the source."
- Coverage
- Geography national · population acquisitions of Swiss citizenship by members of the permanent resident population, calendar year · from 1975 · to 2025
- Gaps
- The total and the crude rate start in 1975, the breakdown by former nationality in 1981. States that did not exist in a year have no row for it ("*" in the source); "…" (not collected) is left out. No canton series kept (the BFS publishes one, je-d-01.05.06.01.02).
- Used on
- STORY-06, PROB-01
- Known limits
- Crude rate (footnote 1 of su-d-01.05.06.01.01): acquisitions per 100 holders of a C permit at the start of the year — until 2010 including holders of L (≥ 12 months) and B permits, 2011–2017 including holders of B permits. The denominator changes in 2011 and 2018, so the rate jumps from 2.26 (2017) to 3.22 (2018) without a matching change in the number of acquisitions; do not read those steps as trends. Sources named by the BFS: 1975–1980 ZAR, 1981–2010 PETRA, since 2011 STATPOP. Cross-checks (2026-11-02): (1) the two BFS tables differ in 1998 (21 279 vs 21 277) and 2001 (27 586 vs 27 583) and agree in every other year; (2) the demographic balance (bfs-population-balance, naturalisations of the Swiss population) gives the same total in every year 1981–2025 except 1998 and 2001, where it matches su-d-01.05.06.01.08; (3) the SEM counts 40 077 naturalisations for 2024 and 41 134 for 2025 (sem-foreign-population), 165 and 462 more than the BFS (39 912, 40 672); the SEM table counts every decision in its register, the BFS the acquisitions by members of the permanent resident population — Votara has not found an official note that reconciles the two (still to be confirmed with the BFS and the SEM). Nationality before naturalisation is not origin; many naturalised people keep their former nationality (see bfs-dual-citizenship).
- Processed file
- data/processed/bfs-naturalisations.csv
How current is this data?
- Freshness
- Up to date
According to its update rhythm, no newer edition is expected yet.
- Period covered
- 1975–2025
- Last change of the data
- Last check of the source
- Update rhythm
- Yearly
Ledger note (in English): Yearly, with the definitive population results in late August; the crude rate table in September (2025 data on 20.08.2026 and 24.09.2026).
- Votara checks the source
- Every week, and every day from 3 days before to 14 days after an announced publication date
The state is computed each time the site is built; this page shows it as of . Results of the accuracy checks
Transformations
- Total and crude rate: XLSX su-d-01.05.06.01.01, columns Jahr · Total (Erwerb des Schweizer Bürgerrechts) · Total (Rohe Einbürgerungsziffer); the rate is rounded half-up to 3 decimals. Script: scripts/fetch/bfs-naturalisations.ts
- By former nationality: XLSX su-d-01.05.06.01.08, read with the bfs-nationality-groups transform (summary block mapped by exact label, first row "Total"; detail rows classified as sub-regions when they equal the sum of the rows that follow; the fetch fails unless the detail block adds up to the total in every year). group = ASCII slug of the German label (same rule as bfs-nationality-groups, so the two join).
- The total rows come from .01; the Total row of .08 is not repeated, and the fetcher warns where the two differ.