Prince Harry and Meghan Markle open office in California

The Duke and Duchess of Sussex have drawn ridicule over a letter they sent to a shop in California.

The letter surfaced as Prince Harry returned to the United States after recording his testimony in London High Court in phone hacking case.

A letter of thanks was  delivered to a shop in California which sent a gift to Archie, the son of Prince Harry and Meghan Markle, on his fourth birthday.

The letter dated June 6 was sent on behalf of the couple from the "Office of Prince Harry and Meghan Markle".

Written on a A4 paper with the letterhead of "The Duke and Duchess of Sussex, and carrying no royal emblem or stationary, the letter said "On behalf of Prince Harry and Meghan, The Duke and Duchess of Sussex, please accept their sincere thanks for thoughtful gift you sent to Prince Archie for the fourth birthday. The bike has brought much joy, and is most appreciated by the family."

The letter was shared on the social media page of the shop which said, "We hope they don’t mind us sharing this lovely thank you letter we received today!" 

It was previously not known whether the couple had an office in California where they are settled after stepping down as working royals.