Northern Rock completed its rebrand to Virgin Money over the weekend, after Richard Branson bought the troubled lender for £747m in November 2011.
When the buyout was announced, the bank committed to no further redundancies for three years.
Virgin was also named today as an informal bidder for 316 RBS branches after its deal with Santander fell through on Friday last week. Private equity group JC Flowers is also said to be interested in making a competing bid as part of a plan to expand the firm's UK lender, One Savings Bank.
The deal between RBS and Santander reportedly collapsed on Friday, after the Spanish bank said it was taking too long to complete. It is thought incompatible IT systems were to blame.
The former Northern Rock business was taken into temporary public ownership in February 2008. Following the restructure of the former business, the new Northern Rock plc was created as a savings and mortgage bank, on 1 January 2010.
Virgin Money said: "We have been working hard to successfully integrate the Virgin Money and Northern Rock businesses this year. All of the branches have been transformed into Virgin Money Stores, the company has now been renamed as Virgin Money plc, and the two websites have been combined into virginmoney.com."
Around 90% of Virgin Money's mortgage business is driven through the intermediary channel.
Ben Thompson, MD Legal & General Mortgage Club, said: "Our hope is that Virgin Money can really ramp up the challenge to other existing major banking players and become a real and credible choice for consumers, forcing price competition and product innovation. The market very much needs this now."