The Prince of Wales' household is waiting to see what impact the UK's decision to leave the European Union will have on the official work of the heir to the throne, a royal source has said.
With members of the Royal Family regularly undertaking official overseas visits in support of UK interests, there is speculation Charles could be pressed into action by a future government to make foreign trips in support of new UK trade agreements.
The development came as the Crown Estate, whose profits are used to fund the official work of the Queen, published end of year figures, alongside separate accounts detailing the official expenditure of the Queen and Charles.
Alison Nimmo, the Crown Estate's chief executive, said they were well placed to weather any fallout following the UK's dramatic decision to leave the EU, which is still having serious repercussions for financial markets left volatile since the referendum decision was announced on Friday.
Accounts for the Sovereign Grant, which funds the Queen and her household's official expenses, show the monarchy cost the taxpayer £40.1 million during 2015-16, with more than £16 million spent on the upkeep of royal palaces and other buildings, up £4.6 million on the previous financial year.
The Queen and the Royal Family's official travel cost the taxpayer £4 million, down more than £1 million.
Charles' private income from his Duchy of Cornwall estate, a portfolio of land, property and financial investments, rose by 3% to £20.5 million during the last financial year, and his tax bill increased by £531,000 to just over £5 million.
Foreign royal travel is used to promote the interests of the UK, strengthen relationships with existing nations, build ties with new leaders as well as support the charitable interests of the individual members of the monarchy asked to make the trips.
Asked if the prince could find himself travelling abroad at the behest of ministers to help with trade deals, the source said: "I think it is way too soon to say. We simply do not know.
"The referendum was only at the end of last week. We have will have to wait and see."
It is understood Charles' household Clarence House is monitoring the political situation very closely and is waiting to assess future developments.
The Crown Estate, a £12 billion property portfolio that ranges from Regent Street in London's West End to Ascot Racecourse, published its annual report on Tuesday showing a record £304.1 million for Treasury coffers.
Under the Sovereign Grant, the Queen receives 15% of the profits from the Crown Estate, but from funds two years in arrears.
The figures mean the Queen is likely to receive an increase in the public money she receives to carry out her official duties in a few years time, if the current formula is maintained or increased.
The percentage formula for calculating the grant is reviewed every five years and is being discussed during the current financial year.
But it is not clear what effect Brexit has had on the progress of the review involving the grant's royal trustees - Sir Alan Reid, Keeper of the Privy Purse, the Chancellor of the Exchequer and the Prime Minister, who will be replaced by the autumn.
A senior palace official has said it is up to the royal trustees to decide the pace at which they move, and it is a case of seeing how the review progresses.
During a briefing to launch the report Sir Alan highlighted the large amount of funds spent on upkeep of the royal palaces: "In 2015-16 spending on property maintenance amounted to £16.3 million and that's 30% of our total expenditure - that's an increase of 39% compared with spending on property maintenance last year."
He stressed that despite the investment they are making, the condition of the estate was deteriorating at a faster rate than they have been able to respond to.
Sir Alan said a significant amount of the increase of the 2016-17 grant, set at £42.8 million, supplemented by other funds like property rental, would be used to increase the annual works programme to tackle the backlog in essential maintenance.
The accounts showed that an apartment at St James's Palace had been refurbished at a cost of £500,000 and was now being rented to a public tenant, whose home was outside the security cordon of the palace.