So here we go , i am european and i live in europe and i pay independently taxes for over 8 years by now .
If you are living in the UE ( union european ) then VAT its working like this :
You go and register yourself as freelancer and you start to pay VAT - the VAT its calculated at every money transaction that will hit your bank account , you practically have to create an invoice from your bank account for any payout you get and to that you pay VAT . ( thats why its recomanded to have a totally separate bank account for your income ) .
In case you have an citizenship and you live in another country you will have to pay VAT for your income in both countrys if you have an living place in the 2 countrys ( i know it sucks ) .
The cam sites itself they are paying VAT yes but they pay it for the profit they get , not for the money that they invoice to us , that means we are always responsable to pay taxes for the money that we recive from the sites because we are independent contractors not employees.
Taxes in EU area are from 17% to 25% , Portugal does an exception with an 14 % for freelancers .
If you make around 45 000 euro ( cca 55 000 $ but always depend of the country minimal salary , you have to sum up the country minimal salary per 13 months ) per year you are forced to register yourself like a home based bussiness whitch will imply more taxes with the possiblility to choose how you want to pay taxes :
a) you pay less procentage from the money that hit your bank account , but then eventually bussiness costs are on your pocket
b) you pay more percentage from the money but only after from the money that hit your bank account , your eventuall bussiness costs and bills and materials were taken off . ( this requiers more attention and beaurocracy but worth ) This is normally done EVERY MONTH ( in small exception - after a few years running your bissiness you are allowed to tax every 3 or 6 months )
Then are those countrys where you have higher taxes pergentage - but you have schools free , public transportation costs less, rent cost less, healthy sistem its included . And are those countrys where you pay less taxes but you have to pay more for rent , public transportation , health sistem and so on.
In both cases if you opt for option b) then you can deduct all bills from taxes , and after the Clean of taxes money are calculated then submit yearly income taxes one more time and you ask taxes back ( like for example adding bills for family , kids and so on )
Hope this helps
PS : I do not know how is in the UK .
Please sorry eventual mistakes , or mixed grammar , hope you will can understand me
If you have any questions please ask , but keep them short and simple
my brain does not react fast when i am very tired
Alsomay be small exception and regulation from one country to another in the European Union , but generally thats the basic guide.