Harry and Meghan, the Duke and Duchess of Sussex, are returning to the U.K. after six years in the United States. The couple is relocating from their Montecito mansion to a private residence outside London, but the timing of their surprise homecoming could cost them valuable tax breaks. Experts say they are leaving potential savings on the table—savings that could be worth millions.

“Whilst their return is welcome news, staying away a bit longer would have given them a much better tax result,” Dhana Sabanathan, leading partner in the tax, trusts and succession team at national law firm Michelmores, tells Fortune.

Under certain U.K. tax rules, the couple forgoes major benefits by returning home now. Because Harry spent only six years away, he missed two key tax advantages tied to a 10-year non-residence period: four years of Foreign Income and Gains (FIG) relief, and the inheritance-tax advantages available to someone who has broken their long-term U.K. residency. Both provisions stem from the U.K.'s April 2025 tax overhaul, which scrapped the long-standing “non-dom” regime in favor of a residence-based system that rewards long stretches abroad.

The missed opportunity is concrete. If the couple's U.S.-based investments grew in value, they could have sold those assets after returning to England and brought the money into the U.K. without owing U.K. tax on the qualifying foreign gains, under the FIG regime. As things stand, Harry's qualifying foreign income or investment gains could now be subject to U.K. tax.

The stakes are significant. Because inheritance tax can run as high as 40%, millions of dollars of his overseas assets could be exposed—estimates put Harry and Meghan's collective fortune at $60 million. Had they waited 10 years before returning home, Harry's non-U.K. assets—his Montecito home and U.S. investments, for example—could potentially have stayed outside inheritance tax for years after his move.

“If they had remained non-UK tax resident for 10 consecutive tax years before returning, they could have enjoyed relief on their non-UK income and gains for the first four years of their return,” Sabanathan explains. “Staying away for 10 years could have also enabled Harry to protect his non-UK assets from inheritance tax.”

There are no public reports of Harry obtaining U.S. citizenship, so he is not subject to the country's taxation upon leaving Montecito for the U.K. California-born Meghan will still have to deal with her home country's tax affairs while living across the pond: the United States taxes its citizens on worldwide income regardless of where they live, so her filings will continue on both sides of the Atlantic. Additionally, since stepping back in 2020, Harry has not collected the public money that working royals receive for official duties.

A potential tax upside: skirting the U.K.'s “temporary non-resident” tax hit

While returning after six years rather than 10 means missing some tax breaks, experts note that the timing of the move also offers advantages.

The Michelmores partner points out that the couple hit six full years of non-U.K. residency, which allowed them to clear the rules around “temporary non-resident” capital gains tax. The country's rule—designed to keep people from moving abroad temporarily—means that if a resident leaves the U.K., makes profits on investments abroad, and returns within five years, the U.K. can still potentially tax those gains as if the person had never left for tax purposes. The couple's six-year timing puts them beyond the scope of this rule.

“They have saved some tax in that by staying outside the U.K. for more than 5 tax years,” Sabanathan says. “Any non-UK disposals they made or non-UK income earned (potentially from Netflix and Spotify deals and Meghan's As Ever brand) during their time as non-residents should not be subject to UK tax on their return.”

Nimesh Shah, CEO of London tax and advisory firm Blick Rothenberg, said on X that the “timing of their move back to the UK is immaculate” for that reason.

The couple's surprise move back from America to the U.K.

Harry and Meghan's decision to move back to the U.K. came as a surprise for some.

Six years ago, the couple chose to step back from their roles as senior working royals, seeking greater privacy and independence while moving away from the pressures of life within the highly public family. They moved to California, where they have earned money through media ventures and commercial deals, including contracts with Netflix and Spotify. They have starred in and produced shows like the documentary series Harry & Meghan and the Netflix show With Love, Meghan, while Meghan has also launched her lifestyle and food brand, As Ever.

Recently, however, Harry has said he wants to reconcile with his royal family. His father, King Charles III, is currently grappling with an undisclosed cancer diagnosis. Some also speculate that the couple's family catch-up with King Charles and Queen Camilla last month at the royal's private Gloucestershire country residence may have helped drive the decision to return to the U.K.; it was the first time the monarch had been reunited with his grandchildren in four years.

According to various sources, the couple's children—7-year-old Prince Archie and 5-year-old Princess Lilibet—have already been enrolled in British schools. It is still unknown exactly which estate Harry and Meghan will settle down in, but it is reported they will live in a non-royal residence right outside London. The famous duo is also reportedly keeping their Montecito property as a U.S. home base—a detail with tax significance, since U.K. tax residence is determined in part by how many days a year someone spends in the country, meaning the family's transatlantic schedule will help shape their ongoing tax position.

This story was originally featured on Fortune.com.