Prince Harry and Meghan Markle privately exchanged personal vows three days before the service at Windsor Castle on May 19, 2018.
On March 8, Victoria Murphy, a journalist specializing in the royal family, tweeted that Meghan and Harry "were not legally married" three days before their wedding and that "Meghan was describing a private exchange of vows" in the interview.
Speaking to the Daily Beast, Harry and Meghan's official spokesperson reiterated that there was no legal marriage. "The couple exchanged personal vows a few days before their official/legal wedding on May 19."
According to the Church of England's Canons, two witnesses need to be present for a legal wedding, and the marriage must take place in a church or an area with a special license. They added that they wouldn't grant a license to anyone to get married at home or in a private backyard.
Therefore, the claim that Meghan and Harry secretly married before the royal wedding is misleading. The couple exchanged vows, but it was not officiated.