I was working for company X(Europe) where I was enrolled in ESPP (Employee Stock Purchase Program). After a few months when I sold the stock I received an offer from the X(US) "the mother company" to relocate to US. Of course I accepted the offer and now I have to file 1040NR/1040 forms. All this happened in the same 2010 tax year.
Questions: Will the IRS consider the ESPP income as US Effectively Connected income, because I guess that the stock was granted by X(US) while I was actually still working for X(Europe)? And do I have to specify this income in 1040NR form (according to irs.gov non-residents have to specify only US Effectively Connected Income)?
Obviously the stock does not show up in W-2 form with the past date because at that time I was actually still employed by X(Europe). The stock does not show up in any other forms as well (e.g. 1042-s, 1099).
So far I already had a consultation with one tax advisor who wants me to report this income in 1040NR. But I somehow do not agree with him and want to discuss whether this income indeed should be considered as US Effectively Connected Income at all...
I would appreciate any answer but would prefer those that can refer to irs.gov website or any other reliable source from US government.