Earnings
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.
Royal allowance
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.
Property
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
