Tax question: just got new contract, but been out of the country over 180 this year..

[sunshinebubble]

I got back to the UK in October and have been in the US travelling so by April I will have been out of the UK more than 180 days. Do I need to fill in a tax exemption form or something so that it is documented?

Also, I just got a new contract and I am invoicing and being paid directly into my bank account. I know I need to set up my own limited company, but I don't really know if I should do that now, or wait until the new tax year

Any advise would be much appreciated!