I travelled round Europe for 15 odd years.

Only paid income tax a few times doing seasonal work for a boss.

I lived in the UK for some years from 2006 and ran a bussiness for a couple of years..Before i registered i asked at the CAB where i stood thinking the tax man might claim i owed a fortune in tax.They couldnt give me a straight answer..It seemed you have to be living in a country for more than six months and keep returning there to qualify.
It a grey area, I never did find out for sure.

I know as soon as you register as self employed or resident they will start wanting some thing.