Re: Tax rebate from B to C permit
I'd be surprised if that is the case, if you really mean a rebate.
Firstly, changing from B to C will mean you no longer pay source tax. So per month you get to keep all that lovely tax money. However, you do of course need to pay taxes, so you will need to pay that at some time in the future. Not what I call a rebate.
If you mean when changing from B to C your friend actually recevied money back from the tax authorities - very unlikely I would say. For a start, how soon after changing did the rebate come ? Normally anything to do with the tax authorities seems to take for ever, and I can't imagine they are specially quick at paying rebates.
Now, if your friend means that after changing from B to C and then subsequently filing a tax return (which is then mandatory) his tax bill was substantially lower than previously when on source tax, there is a chance of that. For example if living in a low tax community within a high tax canton due to the way the tax calculation is made, and especially if able to offset many deductions above the norm e.g. high travel costs, high pension contribution etc.
Certainly in my case I changed from B to C in the middle of the year in Zurich (a few years ago) and there was no source tax refund. It was retained and offset against the taxes due after filing my tax form.