The King will give a £600 bonus from "his own pocket" to staff who earn less than £30,000 a year, it has been reported.
Hundreds of royal workers have reportedly been told they will receive £600 on top of their pay this month.
The cash, which will be given in a one-off payment, is expected to help with the cost of living crisis.
It is expected to go towards the cost of rising energy bills and increased mortgage payments.
Staff who will be given the financial windfall are said to include cleaners, footmen and servants.

Charles, who was then Prince of Wales, asked MoneySavingExpert's Martin Lewis over the summer for a brief on how energy bill rises are affecting people., the Sun reports.
Staff earning less than £30,0000 a year are expected to receive £600 and those on higher salaries will receive a £200 to £400 one-off payment,
The cash bonus, reports claim will not be met by the taxpayer, but will be paid from the King's private income.
Those in Royal Household accommodation provided are expected to be given £200 each.

Staff earning £30,000 and £40,000, meanwhile, will receive £400 extra.
There are 491 full-time staff employed by royal palaces, which are occupied including Buckingham Palace, Balmoral and Windsor Castle
Chancellor Jeremy Hunt is expected to curb public sector pay rises in this week's budget.
Earlier this week The Mirro r reported how the King held an audience with the president of Nigeria at Buckingham Palace on Wednesday - just hours after a protester threw eggs at the monarch during his visit to York.

It was business as usual for Charles back at monarchy HQ as he welcomed Muhammadu Buhari to the official royal residence in London.
During the audience in the 1844 Room, Charles shook hands with the smiling president and was pictured chuckling and gesturing as he held his arms out wide.

Earlier, as the King and Queen Consort arrived at York's medieval gateway Micklegate Bar, a protestor began booing them before throwing four eggs in their direction, all of which missed.
Charles continued shaking hands with dignitaries including the Lord Mayor as the eggs flew in his direction, pausing briefly to look at the shells cracked on the ground.