Prince Harry’s wedding to American actress Meghan Markle could provide a 500 million pound boost to Britain’s economy as tourists flock to the country and Britons celebrate, according to an estimate, Reuters reported.

Harry, Queen Elizabeth’s grandson and fifth-in-line to the throne, will tie the knot with Markle on May 19 at Windsor Castle, the royal palace home of British kings and queens for almost 1,000 years.

There were an extra 350,000 visitors to the UK in April 2011 when Harry’s elder brother William married his wife Kate compared to the same month the previous year, according to the Office for National Statistics.

Business valuation consultancy Brand Finance predicted a similar surge in May and in total, it estimates the nuptials will generate some 500 million pounds ($680 million).

“We think approximately 200 million pounds will come from tourism, travel, hotels,” the company’s chief executive David Haigh told Reuters.

About 150 million pounds would be spent on people having parties and celebrating with 50 million coming from people buying T-shirts, hats and other commemorative items, he said.

The wedding would also be worth about 100 million pounds in free advertising for Britain around the world, he added.