If I were to move from the UK to the USA and leave my tax-free savings accounts (ISA's) open in the UK, with the intention to returning to the UK after 2 years, what would the status of said ISA's be in the eyes of the IRS? Would they charge tax on them?
You should check this with a tax accountant or tax preparation expert, but I encountered a similar situation in Canada. Your ISA income does count as income in a foreign country, and it is not tax exempt (the tax exemption is only because the British government specifically says so). You would need to declare the income to the foreign government who would almost certainly charge you tax on it.
There are a couple of reasons why you should probably keep the funds in the ISA, especially if you are looking to return. First contribution limits are per year, so if you took the money out now you would have to use future contribution room to put it back. Second almost all UK savings accounts deduct tax at source, and its frankly a pain to get it back. Leaving the money in an ISA saves you that hassle, or the equal hassle of transferring it to an offshore account.
From the UK-USA tax treaty.... ARTICLE 1 General Scope 1. Except as specifically provided herein, this Convention is applicable only to persons who are residents of one or both of the Contracting States. 2. This Convention shall not restrict in any manner any benefit now or hereafter accorded: a) by the laws of either Contracting State; or b) by any other agreement between the Contracting States...
I'm not an expert but to me that sounds like the tax free advantage of an UK ISA would be respected by the IRS
From the UK-USA tax treaty.... ARTICLE 7 7. Where under any provision of this Convention income or gains arising in one of the Contracting States are relieved from tax in that Contracting State and, under the law in force in the other Contracting State, a person, in respect of the said income or gains, is subject to tax by reference to the amount thereof which is remitted to or received in that other Contracting State and not by reference to the full amount thereof, then the relief to be allowed under this Convention in the first-mentioned Contracting State shall apply only to so much of the income or gains as is taxed in the other Contracting State.
This is very difficult to comprehend but suggets also that tax free status is upheld in the uSa
Good question - I know you can keep the ISA in the UK and it won't lose its tax free status but you're not able to contribute it while you're not a UK resident. Not that its tax free status buys you that much if you're a non-resident as you could apply to receive tax gross on pretty much any savings account anyway.
Given that the idea of tax-free saving outside a retirement account doesn't really exist here in the US I would assume that you will have to declare the interest as income and, if you don't pay any other taxes in the UK that would cover the amount you'd have to pay on your ISA under the foreign tax credit, you'd end up giving the IRS their pound of flesh.
As I mentioned in an answer to a previous question, you really need to talk to an US accountant/CPA, preferably one that is familiar with UK taxation law as well.