Hello, I am Keith, one of the experts on Just Answer, and pleased to be able to help you with your question.
Where do you actually reside for tax purposes?
I have to tell you that you cannot simply swan about the globe and not be taxed anywhere. You must be taxed in some country and it appears likely that this will be the UK. As you are not an EEA citizen you have no personal allowance so all your income will be taxed at 20%, any over 32K will be at 40% and over 150K at 45%.
Your overall receipts can be reduced by any business expenses wholly and necessarily incurred in your operations.
You will have to register as self employed with HMRC and that Department will send you a self assessment tax declaration for completion annually.