One Canada Square Canary Wharf Management Ltd are responsible for the maintenance of the building. There are about 130 in-house and contract staff who maintain, manage, secure and clean the building. There are normally ten maintenance personnel on-site during working hours and three at night to attend to routine repairs and adjustments to the internal environment. Critical spare parts for the electricity, gas and water systems are kept within the building. One Canada Square has been 'named and shamed' for being the top building to leave the lights on unnecessarily. The research carried out by the BBC's "Inside Out" programme found that on
Asia Square wealth fund, has agreed to purchase the building for S$3.4 billion. Citi is the anchor tenant for Asia Square Tower 1, giving Citi the right to external signage on the building. Tower 1 houses Citi Asia Pacific, Citi Singapore headquarters and Citi Private Bank. Other Tower 1 tenants include the global investment bank New State Corporation, the Taipei-based Global Financial Services Group CTBC Bank at #33-02, China Citic Bank International, Julius Baer, China Fortune Land Development's international HQ, the Swiss National Bank, Bank Sarasin, Lloyd's of London, Marsh & McLennan, White & Case, Booz Allen Hamilton, Royal Bank of Canada,