I work in London for an English company. I will move to NYC and keep working for the same English company for a few months doing researches to open a new business, and my boss would like to keep paying me on my bank account in the UK. Will i have to to pay taxes to both countries? Can anybody tell me how does it work in NY, please? thank you so much
There are more issues involved here: US Federal tax, UK-US tax treaty, NY State tax and NY City tax.
I suggest getting a professional advice here, since the treaty may alleviate some, but not all, of the tax concerns.
Without the treaty - yes, you'll pay both the US (including the Federal, State and the City) taxes and the UK taxes in this scenario.
Yes, the IRS and the state and city of New York will probably all want a bite of your NYC-source income. Your employer should have a process for dealing with withholding and may offer assistance in filing taxes. One important question is the length of your stay (less than 183 days?) and other factors that will influence tax residency (which matters for your non-US income).
It sounds like you have general questions about this issue. You can refer to IRS Publications 515, for nonresident aliens, and 519, for aliens generally, to get answers to technical questions. Page 2 of 519 may be particularly helpful. You may also wish to consult the UK-US Tax Treaty (and protocols and explanations), perhaps in consolidated form.
It may seem overwhelming, but many international and trans-Atlantic companies offer services to their employees to handle the tax aspects. You should be able to discuss this issue with an administrative person at your employer, including any tax advice they will procure for you (i.e. an accountant or preparer) and any withholding they anticipate.