As Beijing steps up its regulatory oversight on capital outflows, residents of mainland China are encountering greater constraints on opening offshore accounts – including outright prohibition – at mainland branches of major Hong Kong banks.As of Monday, the Shanghai branch of the Bank of East Asia (BEA) had suspended opening Hong Kong accounts which allowed overseas investments for those on the mainland, according to an account manager at a BEA outlet in Shanghai’s Lujiazui financial district, who spoke on condition of anonymity due to company policy.Such services had been valued by the bank’s high-net-worth clients who hoped to allocate their assets around the globe, the manager said, adding that the move came as a surprise for bank patrons.The bank’s witness service allows those in Shanghai to set up Hong Kong deposit and investment accounts without leaving the city. However, the privilege does come with conditions; for instance, clients are required to park a minimum of 500,000 yuan (US$73,943) in their domestic accounts.The BEA account manager attributed the suspension to tightened regulatory rules in Hong Kong, where the bank is based, saying “the bank needs time to sort out relevant policies”.Meanwhile, staff members at a Lujiazui branch of HSBC cautioned that all funds deposited into investment accounts must comply with Hong Kong’s regulatory requirements, though multiple workers said the bank was still offering witness services.A spokesperson for BEA told the South China Morning Post that the bank had provided account-opening services to both local and non-local customers in accordance with regulatory requirements. “We are following the latest guidelines from relevant regulators to ensure that the account-opening process is both compliant and efficient,” the spokesperson said.