After being put through the rigours of the US tax regime, and being faced with a humungous tax bill that could wipe out a lot of investment gains, many investors might be thinking that they may not want to be US citizens any more.
But it is not that simple.
Sigita Dromantaite, director at US and UK Eagle Taxation, says: "What happens is, after this calculations with PFIC, people start thinking 'I don't like America anymore'.
"'I lived there 20 years ago, why do I care about this, and why do I need to pay tax?' We start to look at reducing that side of things."
Ms Dromantaite says that she will look for an emotional connection to America, and will look at the client's worldwide assets.
If the client has less than $2m of worldwide assets, then life is a lot easier; if they have above $2m then there is a 40 per cent tax charge on any gains made on these assets.
But "assets" covers everything; it is not simply investment portfolio, property and savings.
It covers household effects, jewellery, cars, kitchen equipment even, but not quite as far as the underwear drawer.
Key points to remember:
- US citizens may be tempted to give up their citizenship.
- If one has more than $2m in worldwide assets then one is facing a tax bill.
- Being a US citizen means lots of form-filling.
Queen and country
If the client has less than $2m of worldwide effects, then there is only the emotional impact of leaving.
She says: "Never go to an embassy and say 'I'm giving up my citizenship for tax reasons'.
"Say 'I love the Queen', otherwise they may choose to keep you in the tax system for 10 years."
Aside from not owning up to the real reasons for leaving, Rajiv Vadgama, tax partner at RSM UK, says the process of giving up citizenship is relatively straightfroward.
He says: "You need to fill out a form at the US embassy, and renounce your US citizenship. You will have an interview and they will give you the ramifications.
"There's a cost attached to it of $2,000 to $3,000."
If a client has more than $2m in worldwide assets, it means you have to do some tax planning, and an adviser should look to find a reputable tax accountant.
There are other practical issues to consider about giving up citizenship. According to Mr Vadgama, these include being flown through customs very quickly, rather than waiting for ages like everyone else.
But on the other side of the equation there are other issues to consider. Mr Vadgama reveals there is a whole lot of form-filling that has to be done, both by the individual and the bank that holds their money.
Under the Foreign Account Tax Compliance Act, US citizens have to report their overseas financial assets to the US authorities, and the banks where they keep their money also have to report to the US any details they have about US clients.
This means that many banks do not like to take on US clients because of the extra work involved.