For residents of most developed countries, opening bank and stockbroking accounts abroad is not difficult. But for US residents, it can be a bit more awkward.
On the domestic side, there is little to stop you opening offshore accounts. US law only forbids you from sending money to a small number of countries: Iran, Cuba, North Korea and so on.
And you must declare your accounts and pay US taxes when required (see below for an important warning on this). But assuming you stick to these rules, the US government doesn’t care much where you put your money.
The problem arises at the foreign banks and stock brokers, many of whom refuse to deal with US clients. And responsibility for this lies with some overly broad rules implemented by the Securities and Exchange Commission (SEC) – plus the threat of new tax legislation.