As far as I know, C permits are not limited by time at all, but there are simply control check periods e.g. every 5/10 years.
As an EU person, the difference between B and C is not that great (firearms, voting). Although that could change with immigration vote etc.
It took 4 days here from the day my OH handed the B permit renewal form in and him going to collect his new C permit.
They didn't ask for any documentation whatsoever.
If they can check the records so easily without our knowledge why do some cantons ( not NE) ask for a copy of the debt register, income etc when renewing?
Surely it would just be simpler and quicker for them to do it themselves.
An idea, but I think some cantons look at the data privacy laws differently. If you get a copy of your own private details and give it to them, they can't be held responsible for the data confidentiality being lost.