Scoban, which will unveil the bank's trading name later this month, has finally been given the green light by the regulators for a 'mobilisation process', and will open its doors within months.
Mr Entwistle said Scoban had raised £4 million from its initial backers and was now in the market looking for a further £36m from institutional shareholders or family houses.
He added: "I can tell you we didn't need to raise all that money to have our licence, but we are raising that sum of money because actually we know that the business that has been promised to us will require us to have that amount of capital."
Most of the initial £4m was raised by the end of 2011, and Mr Entwistle originally hoped to open the bank by the end of 2012, but the former Financial Services Authority was stipulating that it might have to raise at least £75m of capital.
Last year, with two new regulators in place and following a consultation process in which Scoban had a significant input, entry requirements were overhauled and the new capital target became £30m. By the time the licence application was finally submitted last September, Scoban had hired a banking and IT team led by former Scottish Widows Bank managing director Graeme Hartop, and had moved in to its Charlotte Square base.
Mr Entwistle said both the Financial Conduct Authority and the Prudential Regulation Authority had been businesslike and supportive. "The Treasury are on side, the Government is on side, and here we are in Charlotte Square, a new Scottish bank - it's pretty exciting, and quite an achievement."
Scoban has not applied for a wealth management licence, and hopes to forge partnerships with wealth managers whose clients may be attracted by the promised "traditional" banking service. Mr Hartop said: "We will open our doors later this year in Edinburgh and London, with a very experienced team of bankers, whilst at the same time employing a number of young people to be trained as bankers for the future."