The BBC’s royal correspondent Peter Hunt understands the meeting is not about the health of either the Queen or Duke of Edinburgh, according to the BBC.
Officials at the palace have not said what this morning’s meeting, reported to involve all senior staff from across the UK, is about.
Such internal royal meetings usually happen about once a year.
Thursday’s meeting will take place at 10:00 BST.
It comes after the Queen and Prince Philip fulfilled official duties on Wednesday.
The Queen met Prime Minister Theresa May at Buckingham Palace to formally agree the dissolution of parliament ahead of the general election, while Prince Philip attended Lord’s Cricket Ground to open a new stand.
He was heard joking at the event that he is the “world’s most experienced plaque unveiler”.
On Thursday, the Queen and Prince Philip are due at a service for members of the Order of Merit at the Chapel Royal at St James’s Palace before hosting a lunch for those attending.