I'm helping a friend with his UK self assessment (having done it for myself last year), but his is much more complicated than mine.
He is a US citizen, thus required to file and pay US taxes on world-wide income even though he is a UK resident. What I'm trying to figure out now is whether the same is true for the UK as well? He has some US income where all related expenses and income are solely within the US (e.g., he purchases stock during a visit to the US and sells it there as well) - does this need to be reported to HMRC, or only to the US?
Thanks very much.