After that period, the US-born actress can then apply for UK citizenship, or potentially dual citizenship for the US and UK.
This means during the time she waits to become a British citizen, Meghan will be expected to cough up tax to the International Revenue Service (IRS) on any income she makes.
Avani Ramnani, director of financial planning and wealth management at Francis Financial: “US citizens, green card holders, and permanent residents are required to file tax returns with the IRS every year no matter where they reside.
Meghan Markle could be forced to pay double taxes
If Meghan Markle accepts an allowance from the royal family, which boasts a fortune of approximately £355million, she will also have to pay US taxes on that money.
America’s citizenship-based taxation system is unusual – only Eritrea has a similar system.
But it is founded on the basis of the Civil War and the Revenue Act of 1862, which outlined the need for taxing of US citizens abroad.
Ms Ramnani told Business Insider: “The key for Meghan and her advisors would be to figure out what type of income she will be getting.
“Will this income be from the investments of a trust, or ‘wages’ for any work that she does, or any other type of income? Sometimes, getting one form of income is more advantageous than another.”
Meghan will have to marry Harry within six months of obtaining her visa to maintain her status as she has entered Britain as the fiancee of a British citizen.
Prince Charles’ estate, the Duchy of Cornwall, made £20.7million profit last year.