As the royals meet at Sandringham today for a crunch summit to decide the Duke and Duchess of Sussexes' future, the couple's tax affairs will be under discussion along with their royal titles, Met Police bodyguards and their Windsor home, Frogmore Cottage.
Aides are understood to have already drawn up a potential blueprint for Harry and Meghan's new life in North America, but with "complicated issues" still to be resolved, the Queen's desire for a swift resolution is by no means guaranteed.
While the 93-year-old monarch wants the situation sorted by close of play on Tuesday, sources close to the Sussexes say they "are not going to quickly sign off their future and their lives".
Well-wishers cheered the monarch as she made her weekly trip to a church at her Sandringham estate in eastern England on Sunday.
Later on Monday, the Queen, the Prince of Wales, the Duke of Cambridge and the Duke of Sussex will be presented with "a range of possibilities for the family to review". The Duchess of Sussex, who is currently in Canada with baby Archie, is hoping to join by phone, time zones permitting.
As an American citizen, Meghan already has to pay tax in the US on any global earnings regardless of where she lives. Discussions are likely to include whether the former actress wants to continue with her application for dual citizenship, the status of which is currently unknown.
A full relocation to North America and relinquishing of royal roles would avoid the double taxation but may land the couple with a large bill to repay the £2.4 million of taxpayers' cash spent on Frogmore Cottage.
If the couple wants to retain the Grade II listed property as their UK base then the Crown Estate, which owns the freehold, could offer to lease it back for an agreed annual sum.
Future royal role
Sir Mark Sedwill, head of the Civil Service, has been drawing up plans to offer Harry and Meghan a high profile Commonwealth role, which would allow them to live in Canada and travel abroad on a certain number of official trips each year - allowing them to be 'quasi' royals. Harry is already the president of The Queen's Commonwealth Trust, while last year Meghan was made vice-president - and it is a cause close to the Queen's heart.
But a source warned this 'half in half out option' which would see the royals promote their charitable endeavours as well as their commercial interests as "very difficult to pull off".
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It remains to be seen whether they would still attend major royal events such as Trooping the Colour or need to seek permission for commercial endeavours. Patrick Jephson, the former private secretary to Diana, the late Princess of Wales, questioned whether British embassies would be instructed to support the couple and what level of cooperation would be offered by law enforcement and intelligence agencies.
On security, Dai Davies, the former head of royalty protection dubbed an idea to down grade the couple's armed protection to officers carrying Tasers as "nonsensical". Another option would be to reduce the number of tax-payer funded protection officers and top them up with private bodyguards, paid for by the couple.