Meghan will have to declare any fees she receives from playing Rachel Zane in Suits. She was estimated to earn $50,000 (£36,000) per episode.
Her final season starts next month but Meghan will receive repeat fees – ‘residuals’ – every time it is rebroadcast. The show is now extensively broadcast around the world.
Her annual salary was estimated to have totaled $450,000 (£324,000) before she met the prince, which included money from acting and sponsorships.
Markle now has no sponsorship deals and it is unlikely that she still has income from previous contracts.
Meghan will have to tell the US taxman if she receives anything more than $100,000 (£71,600) from her fiancé or his family in the form of a royal allowance to cover expenses.
Since the age of 21, Prince Harry and Prince William have been receiving an estimated $450,000 (£324,000) a year investment profit from their late mother’s $29.9m (£21.5m) estate, on which they pay UK taxes.
The two princes and William’s wife, the Duchess of Cambridge, also receive an annual $4.88m (£3.5m) allowance from their father, Prince Charles, which is used to cover expenses like travel and wardrobe.
Nottingham Cottage – the grace and favor property in the grounds of London’s Kensington Palace where Meghan lives with Harry – may be taxed by the US if Markle’s presence in it is seen as a substitute for income before her marriage.
Her tax preparer may advise her to declare it to avoid any ambiguity.
While she was filming Suits, Meghan rented a three-bedroom, two-bathroom home in Toronto’s Seaton Village, thought to cost around $1,770 (£1,000) a month.
Meghan also has to give the US taxman full details of her finances if she and her husband-to-be have joint assets, bank accounts or offshore trusts in excess of $200,000 (£143,100).
Once married, Meghan would also have to make that declaration. In the U.S. couples file jointly and all assets are considered joint. However, because Meghan will be married to a non-resident, non-citizen, that will not apply to him.
There is one future – extremely unlikely scenario: if Harry becomes King with Meghan as Queen, the US taxman would take an interest in the British royal family’s fortune estimated at $500 million (£360 million) and made up of property, art and investments. However, he is sixth in line to the throne, so such a detailed return is unlikely to ever happen.
It’s not just the US taxman that wants to take his cut from Meghan.
The actress will have to declare any luxury gifts she bought in the US for Prince Harry, the Queen and his family to the UK taxman – or face a hefty fine.
Gifts over $188 (£135) imported into the UK from outside the European Union are liable for customs duty and VAT.
Customs duty is charged at a rate of 2.5% on gifts between $188 (£135) and $877 (£630).
Above that threshold, the rate depends on the type of goods and where they came from.
VAT of 20% is also charged on the total value of the goods. The maximum penalty for not paying customs duty is $3482 (£2,500).
But a person caught for the first time is likely to receive a minimum penalty of $348 (£250), depending on how serious the contravention is.