IG's standard T&C for UK customers says on this -
<<United States customers
Under existing US legislation, we are unable to enter into spread betting transactions with US residents.
US Customers are defined as:
•any natural person resident in the US (other than on a short term basis); or
•a corporation or partnership incorporated or organised in the US, but excluding an offshore branch or agency of a US person that operates for valid business reasons and is engaged and regulated as an insurance company or bank; or
•a branch or agency of a foreign entity located in the US; or
•a trust of which the trustee is a US person, unless a non-US person has or shares investment discretion; or
•an estate of which a US person is the executor or administrator, unless the estate is governed by foreign law and a non-US person has or shares investment discretion; or
•any account held for the benefit of a US person.
In general, the information on the site is not directed at residents of the United States or any particular country outside the UK and is not intended for distribution to, or use by, any person in any country or jurisdiction where such distribution or use would be contrary to local law or regulation. It is the responsibility of visitors to this site to ascertain the terms of and comply with any local law or regulation to which they are subject. Whilst IG Index has made every effort to ensure the accuracy of the information on this site, the information is subject to change, often without notice. It is for guidance only and no liability is accepted by IG Index for its accuracy or otherwise.>>
This is ambiguous on its own. They say you can SB if you are just a short-term resident of the US, but not if the offer to you of their service is against local law, which it is.
I would be cautious, regardless of what the company say. It might be that the company will not prevent you SB-ing from the US (they don't want to upset and lose a customer) but may feel they could be released from their normal contract and duty of care with regards anything that happens to your account while you are there. It would be a shame to have a series of winning trades that the company later refuse to recognise, and which the FSA might say occurred outside their jurisdiction.
