I'm a Pakistani citizen who has previously lived in Sweden for 3 years on permanent residence against my own self employment visa, but I have since moved on. The Swedish version of what is called social security number, social insurance number, government service number, or otherwise, is the personnummer. I got a personnummer assigned shortly after arriving and registering in the country. Does this personnummer remain valid for the rest of my life, or is there some expiry? How do I check the status of my permanent uppehalstilstand, which is the Swedish version of permanent residence? I have a sticker on my passport which says validity is indefinite.