Queen Elizabeth II is apparently considering retiring in about 18 months so her son, Prince Charles, can assume the throne, reports in the UK said Wednesday.

The 93-year-old monarch is weighing stepping down around her 95th birthday, the same age that her husband, Prince Philip, withdrew from his royal duties, sources told the UK’s Express.

“Her Majesty is mindful of her age and wants to make sure when the time comes, the transition of the Crown is seamless,” a former senior member of the royal household told the outlet.

“I understand the queen has given the matter considerable thought and believes that, if she is still alive at 95, she will seriously consider passing the reign to Charles.”

The Sun also reported that there was “renewed talk” behind palace walls about the Queen stepping down when she turns 95.

“Planning for Charles to become king has been going on for some time,” a royal source told the outlet. “A transition is plainly already underway.”

The queen — the world’s longest-reigning current monarch — won’t be able to officially retire without abdicating her throne, according to royal succession rules.

But she would be able to stop all of her royal duties if her health were to become a concern.

In that case, a regent, most likely her heir, 71-year-old Charles, would step in as a placeholder, Express reported.

The Prince of Wales has stepped in for the queen in recent years, as she’s gradually cut back her official engagements.

He also reportedly played a key role in dealing with the fallout from his brother Prince Andrew’s train-wreck interview about his friendship with convicted pedophile Jeffrey Epstein.

Even though Charles was in New Zealand at the time, he reportedly insisted that “Andrew has got to go … it is the only way,” in phone conversations with their mom.

“The scandal surrounding Andrew and Epstein gave Charles an opportunity to step in to show that he can run The Firm,” a source told The Sun.

“No one is bigger than the institution of the Royal Family. Not even Andrew, the Queen’s favorite son,” the source said. “Charles recognized that and acted decisively — like the king he may well soon be.”

Some palace insiders even reportedly dubbed Charles the “Shadow King” over how he handled the scandal.