Hello!
I am a European facing the same problem as you. I do not AT ALL like the answers of STEVE, although his intentions may be good...
The US tax regulations are NOT "QUAINT". The United States is the only nation in the world to tax (a) its citizens who live abroad and (b) even foreign citizens who live abroad (what..??! it can't be but.. believe it!!).
The tax laws are not "Quaint". If you are a US citizen you are subject to very heavy reporting requirements such as declaring all foreign bank accounts etc. If ever during your expatriate life you let lapse your duties you will heavily pay and possibly lose everything to an IRS audit even if you live abroad or in Canada. Wake up, dual nationals!!!!
In my country, the US tax laws result in (a) no tax (but no reimbursement either!!!) in years when european
taxes are above US taxes - for example, during your work career when earning a salary and (b) ADDITIONAL US taxes in years when US taxes are above european taxes. This means that while working, since taxed at 60% in Europe, we will not be taxed in the US. But as soon as we retire, all capital gains, pension plans etc... (which are built into the 60% work tax during younger years of course!!!) will be taxed by the USA since not taxed in my country! Which means I live in the 3RD HIGHEST TAXED COUNTRY IN THE WORLD and I WILL PAY SUPPLEMENTAL US TAXES FOR THE REST OF MY LIFE AFTER RETIREMENT.
This is ridiculous!
Many of us, like your son, never *chose* to be American. And getting rid of the US nationality has become complexe and terrifying, considering the threats of banishment (which ps are against the 15th article of the human rights declaration which allows people to freely choose their nationality).
I made the (HUGEST) mistake of obtaining USA nationality for my kids. I thought it was the right thing to do at the time. Little did I know that they would be LESS FREE as dual nationals, than if they were purely European nationals (as they would be if I had not taken my stupid initiative). Now they are dual citizens, subject to US laws and taxes, and worst of all face total banishment in the event that they choose
Europe over the USA.
None of this is quaint, adorable or cute.
Your son will be subject to US reporting requirement for the rest of your life, live under the threat of an IRS audit and confiscation for the rest of your life, in addition to obeying the laws and practices of the country you live in.
My advice to you is encourage your son to expatriate within 30 days of his 18th birthday. There are numerous allowances made in the laws for people who do this.
If he lives abroad at that time I believe that they will be more understanding of his case. However the fact that he may have lived over 5 years in the USA could aggravate the case.
As for the true risk of banishment from visits etc. There are a lot of scare mongers on the internet, like Steve. Be realistic. If you don't pay US taxes, you cannot work or live year round in the US. Fair deal. But so far, to my knowledge, they do not banish ex-us citizens from entry on a tourist visa. You just have to understand that if you expatriate, you become a true foreigner, subject to the same visa requirements as other foreigners in your country, no more, no less.
Well, thanks to the wonderful US nationality, you will now have to consult an extremely expensive immigration lawyer and possibly more expensive tax lawyer to get him out of this situation.
I wish you lots of luck; we have been working on our case for a year now and still have no clear solution. Good luck & big hugs to everyone in our situation.
Good luck.