need for tax return if living aboard

Hi, I would like to ask questions about tax return related to online trading. My friend is not uk citizen and not living in uk. She has no NI number. If she uses uk online platform, eg ebay, to sell both goods for profit and unwanted/used products, in which the revenue (expense not deducted) is more than £1,000. Will she: 1. Need to submit self assessment 2. Entitle to have personal allowance Thank you

Hi bobo1,
Please refer to guidance here:
Tax on your UK income if you live abroad
Selling online and paying taxes - information sheet
Thank you.