temran

Hello, I am a NOT a resident of the UK. I recently started doing some part time work completely remotely from my non-EU home country for some UK businesses and individuals. I am a sole trader, not a ltd company, but registered my business using a business address system and follow all the laws and regulations. I also earn monies in my home country and since it is salaried, the tax is automatically taken. There is a double taxation agreement between my home country and the UK. I would like to pay the tax for my UK earnings to the UK. I understand that people like me need to use a software to fill in self-assessment tax return and use SA109 form or send it by post. May I please learn whether I would be eligible for personal allowance for the income I earned from the UK? Additionally, I can't find the form SA100 to complete by hand and return by post, could you please direct me where I can download that form? (due to non residency, I am not allowed to file it online I have to do it by post). Thank you.