Renouncing your U.S. citizenship starts with a hefty fee - $450 (U.S.), just for the chance to appear in front of a consular official. Need it done in a hurry? Forget about it. It can take about two years to get an appointment.
You have to do it in person
Once you've made the appointment, the process is pretty simple. Show up at a consular office in a foreign country, appear before an official and sign an oath of renunciation. You can't do it in the United States, via mail or via another person. But before you take that final step....
You can't do it half way
Giving up your U.S. citizenship means giving up all of your rights and privileges. If you indicate that you want to hang on to a few — say, the right to travel on a U.S. passport and live in the U.S. in the future — your request will be denied.
You run the risk of statelessness
If you haven't made arrangements to be a citizen of another country, you could end up stateless, making it difficult to travel. Also, you can still be deported back to the U.S. if you run into legal problems elsewhere.
You can't escape Uncle Sam
Renouncing your citizenship does not release you from military service, nor does it protect you from prosecution for crimes committed in the United States, and most importantly — it does not release you from your tax obligations...
In fact, you may end up owing him
Before renouncing your citizenship, you have to pay all back taxes and an exit tax. 45 per cent on the market value of all your worldly property, including pension plans, goes to the government. The first $636,000 in capital gains is exempt.
You can't renounce on behalf of your children
Anyone under the age of 18 has to convince an official they know what they're doing. If they wish to reinstate their citizenship after they turn 18, the option is there (for just six months), but...
For everyone else, the act is irrevocable, short of a judicial appeal.