No matter how long you have been in the UAE, you have to keep close tabs on your home country to make sure you are investing in the most tax-efficient way.
Mike Dickson, an oil industry worker who has lived in the UAE for five months and been an expatriate for 15 years, plans to retire in the United Kingdom, but he doesn't want to pay tax there until he does.
He has recently been reorganising his pensions and investments, after taking advice from the Dubai-based advisers Guardian Life Management. "They recommended a savings vehicle that is based in the UAE, but subject to Guernsey law. It allows me to invest in a wide range of offshore funds that will grow tax efficiently until I return to the UK."
He has also transferred an old UK personal pension and a company pension into a flexible, low-cost self-invested personal pension (Sipp). "Sipps are increasingly popular in the UK, and should be a flexible and tax-efficient place for my retirement savings even after I return home," he says.
The 50-year-old Scotsman, who lives in Dubai with his wife and six-year-old son, also keeps an eye on Scottish politics, where there will be a referendum on independence from the UK in September 2014.
"I don't think Scotland will vote for independence, but if it does, the new government will no doubt be looking to maximise tax revenues, and could target Scots around the world. I need to invest carefully, just in case."
Just because you no longer live in your home country doesn't mean you won't be asked to pay a hefty tax bill over there.
The long arm of the taxman can stretch for thousands of miles and with tax and residency regulations changing all the time, you could pay a hefty price if you don't keep on top of developments at home, especially if you plan to retire there.
What follows are some of the dangers facing expats from different parts of the world.
If you're a British expat, your income and investments could be hit by tough new residency rules, says James Thomas, regional director at Acuma Independent Financial Advice. "The statutory UK residence test is changing, and although that won't affect every expat, it could have major consequences for a significant minority."
The new test, which came into force from April, has two parts. "The 'automatic residence test' sets out how many days you can spend in the UK each year before you have to pay tax. This is reasonably clear, but the second, the 'sufficient ties test', is more complex."
This assesses your ties with the UK, including family, accommodation, and how you divide your time between different countries. "The more ties you have, the fewer days you can spend in the UK before you are treated as a resident. This will range from as few as 16 days to as many as 182 days in any tax year."
The rules are complex, and designed to catch more people than before. "Once you are classed as UK resident, your entire worldwide income is liable to tax. Most expats won't be affected by these rules, but it will have a big impact on those who are, so check your status now," Mr Thomas says.
Expat Indians and Indian residents are taxed in the same way when investing in the country. They pay 20 per cent tax on long-term capital gains and 30 per cent on short-term capital gains.
Still, UAE-based Indian expats should be taking advantage of the falling rupee to invest in property back home, says Honey Katiyal, chief executive at the real estate investment advisers Investors Clinic.
"The 25 per cent depreciation in the value of the rupee over the last eight months has presented a real opportunity. One dollar now buys 58 rupees, against a long-term average of around 48 rupees.
"Investing in property in a systematic manner over the next three years should give you a good hedge against future currency movements," Mr Katiyal says.
The US is virtually unique in requiring all its citizens to report their income to the Internal Revenue Service (IRS), wherever they live, says Chris Ferguson, managing director at Guardian Life Management in Dubai. "Under the new Foreign Account Tax Compliance Act, global banks and other financial institutions with US clients are also obliged to report their account details directly to the IRS."
The cost and complexity is persuading many to cut their services to US clients, or withdraw them altogether.
"The unintended consequence is that US expats have a shrinking number of savings and investment options, forcing many into expensive, less tax-efficient alternatives," says Mr Ferguson, who adds that US expats need to assess what investment options remain open to them. "They should make use of any double taxation agreements, and build their retirement savings using transparent, IRS-compliant tax reporting facilities."
Many Europeans have come to the UAE to escape hefty taxes at home, but this freedom could be under threat, says Mr Ferguson. "The global downturn and single currency crisis hit European countries hard, and many are changing their rules and regulations to boost tax receipts. So far, this has been restricted to residents or those holding assets locally, but that could change."
Cash-starved European governments could target expats living and working in the UAE and beyond, Mr Ferguson says. "You should review your investment vehicles and financial plans regularly, to make sure you don't get dragged into your home country's tax net in future, even inadvertently."
Regulatory disruption isn't the only threat. "You should also keep a close eye on the fate of the euro, given the debate on whether the single currency can survive in the long-term," Mr Ferguson says.
Middle Eastern expats
Expat investors from other Middle Eastern countries fall into two camps, says Steve Gregory, managing partner at Holborn Assets in Dubai. "The western-educated tend to look for experienced independent financial advisors who are qualified in their home country, the rest typically go to their bank for advice."
Unfortunately, some banks employ poorly educated sales staff who can sell only a restricted list of products, leaving many investors vulnerable to inadequate advice.
Many Middle Eastern expats also get poor tax planning advice, says Mr Gregory. "They don't have to worry about paying tax on their investments while in the UAE, but unless they prepare carefully, they could face a big tax bill when they get home."
It therefore makes sense to employ an adviser from your home country, who understands the local tax rules. "Many will use an Arabic-speaking adviser, and want Islamic products. These expats need to choose their adviser carefully, and make sure they can offer full financial planning, rather than simply selling savings plans," he adds.
There was bad news for Australian expats in May, when they lost their 50 per cent discount on capital gains tax, says Craig Holding, managing partner at Acuma Wealth Management in Dubai.
"This will affect any profits UAE expats make from property, mining, foreign assets, Australian shares and managed funds. The change was announced a year ago, yet many are still unaware of the implications."
The good news is that any profit before May 8 will still be taxed under the old regime - "but only if you have an independent valuation to estimate the asset's value on that date," Mr Holding says.
Taxing property owned by non-residents is an easy target for the Australian government, as it won't affect most voters, but the tax change will deter many expats from investing in the country's property, Mr Holding says.