Commonwealth Bank has made a couple of enhancements to its retail digital banking service, adding a "Photo a Bill" facility and instant account-opening functions to the Commbank app.Photo a Bill uses optical character recognition technology to convert a document into data, enabling the customer to take a picture of a bill and then pay for it using Commbank.Instant banking allows an existing or new to bank customer to have personal details verified, open an account and put funds into the account in minutes. Using the Commbank digital wallet capability the customer can start transacting before a payment card arrives in the mail.Commonwealth Bank group executive for retail banking services, Matt Comyn, said the bank had 5.6 million active digital customers, of whom 3.6 million are "mobile only".Customers log in to the digital platform 22 million times a week and 70 per cent of log-ins are through a mobile device.Comyn said the core of the digital customer base has been among 18 to 34 year olds but now the growth is among 40 and 50 year olds.Since the bank launched the lock, block and limit facility on its credit cards last year, 800,000 customers have used it - 25 per cent of the card customer base.Its tap and pay facility, which allows customers to make contactless payment using their smartphones, has 860,000 active customers making a total of 2000 transactions a month.The cardless cash facility, which allows customers to arrange an ATM cash withdrawal without a card, has been used by 900,000 customers.An important development for the bank is that 21 per cent of retail sales are through the digital channel. Customers are not just logging in to check their account balance or pay a bill.Twenty six per cent of personal loans are sold online, 46 per cent of credit cards and 17 per cent of transactions accounts.Less than five per cent of mortgages are sold online. Comyn said customers still wanted guidance and face to face contact when looking for a home loan."We want to give customers choice and have a digital-only channel for each product," he said.Unlike some of its peers the CBA is not culling its branch network. Comyn said that the count would be 1000 at June 30 - about ten fewer than a year earlier."Eighty per cent of our highest value customers still use branches. As preferences shift we will shift but proximity to a branch is still important to customers and we see that remaining the case for some time," he said.