Americans abroad have just about had it with Uncle Sam's tax filing requirements.

Those were the findings from a recent survey of more than 2,100 U.S. expatriates, according to Greenback Expat Tax Services, which specializes in working with American taxpayers residing overseas.

Just over 4 in 10 respondents said that while they aren't planning to renounce their U.S. citizenship, they wouldn't rule it out, and 19 percent said they're seriously considering it.

Half of those who are either planning or considering giving up their citizenship say the primary reason is the burden of U.S. tax rules.

"Tax requirements like the Foreign Account Tax Compliance Act (FATCA) and the report of foreign bank and financial accounts (FBAR) start to become more painful for people and they write to their congressperson, seeking action," said David McKeegan, co-founder of Greenback Expat Tax Services and an American residing in Indonesia.

"There's nobody lobbying on the behalf of these people and fighting for your average American living overseas," he said.

Here are some of the tax issues facing the estimated 9 million Americans who live abroad.