I think that you will need accounting services not only for business, but for any sorts of financial transactions. I also run businesses, but aside from that, I am a professional forex and crypto trader. Let's say I registered at theforexcomplex.com and earned $880 after following their strategy. Who is in charge of tax payment? You. So, you'd better know that all your income is taxable. Even if you let your flat to your neighbor, you will have to pay tax.