Weird that you haven't received your invitation to the impending royal nuptials yet.
It probably got lost in the mail.
In the meantime, it's probably wise to focus on finding accommodations.
Preferably somewhere that's pro-freestanding bathtub and anti-not-having-a-champagne-bar.
This was once Kettner's, one of the first French restaurants in London, which closed its doors in 2016 after a 149-year-run. The new management just reopened the restaurant—more on that later—and opened 33 guest-rooms above it.
Each would earn Oscar Wilde's seal of approval, considering all the hand-painted wallpaper, antique chandeliers and freestanding bathtubs about. Though all others pale in comparison to the Jacobean Suite, which features original Edwardian woodwork and its own private entrance for use by secret paramours and pizza delivery guys alike.
Not that you'll even be hungry later, because the restaurant downstairs that once served Winston Churchill and Margaret Thatcher has been revived to serve you steak tartare and roast duck in ostentatiously Art-Deco surroundings. They've also added a champagne bar, which serves its very own teatime menu.
Think normal teatime, normal tiny sandwiches, just more champagne.