Alec S Luhn

I'm an American citizen and tax resident in the UK. US taxes are based on the calendar year. When I did my 2023-24 UK tax self assessment, I used the 2023 calendar year for my US interest, divided and capital gains income, but I used the UK tax year for my US/UK self-employment and US rental property income. Can I use the calendar year for self-employment and rental property income as well? That would greatly simplify my tax, which I have to file in both countries. Thank you.

Hello, I'm a sole trader freelance journalist, but I also own a rental home in the US. I'm being asked if how many self-employed businesses I have. My US rental home doesn't count as a self-employed business, does it? What about US investment income?