In May 1818, the house was purchased from Davy by Henry Ritchie of Busbie. Ritchie was a Glasgow merchant, a partner in the Thistle Bank, and the owner of landed estates in Lanarkshire and Ayrshire. He sold his Charlotte Square townhouse to Charles Oman, a hotel keeper and vintner, in May 1825. Oman, a native of Caithness, had owned various hotels and coffee houses in Edinburgh over the decades, including the Waterloo Hotel on the city's Waterloo Place up until his purchase of 6 Charlotte Square. Oman turned his new townhouse into Oman’s Hotel, which it was to remain for over 20 years. The fixings for the letters of the hotel's name can still be seen today on the exterior wall above the front entrance door of Bute House.