Barclays has closed six data centres and reduced thousands of servers since mid-2013 as part of its cost-cutting efforts.

The bank is in the process of carrying out is 'Transform' programme, which is designed to help the bank reduce its net operating expenditure by £1.7 billion to £16.8 billion by 2015. The programme includes restructuring the business, redundancies and investment in technology and new, more cost-effective ways of working.

In its 2013 full-year results published today, Barclays said that its costs to achieve Transform totalled £1.209 billion in 2013. The majority (£852 million) of this related to the cost of reducing the scale of activities and redundancies in its retail and investment banking businesses.

"Other Transform costs of £356 million were primarily driven by investment in technology and process improvements that will reduce future operating costs and enhance customer and client propositions," the bank said.

As part of these costs, as well as closing data centres, Barclays said it had reduced its number of servers by 6,000 since H1 2013, and decommissioned and retired legacy applications.

In terms of investment in process innovation, the bank said that it was investing in channel migration "towards digital", with the take-up of mobile banking affecting traditional channels.

"The number of customers using digital channels grew substantially in 2013. Mobile banking usage increased by 150 percent to 2.3 million customers and Pingit users doubled to over one million customers," the bank said of its UK retail and business banking division.

It had also introduced more automation and self-service facilities in its Africa bank branches.

Meanwhile, Barclays announced it was cutting up to 12,000 jobs this year, which would include 820 senior managers. Half of the senior management redundancies will be in the investment banking division, the bank said.

To date, Barclays has already made 1,400 redundancies affecting technology and front office staff in its investment bank business. An exact breakdown in IT job losses in this division was not provided.

As a group, the bank has so far cut 7,650 jobs as part of Transform, which it expects to lead to £815 million of annual savings in 2015.

Last month, Barclays announced plans to cut 300 back office IT and operations roles at its corporate banking division, mainly affecting staff at its London office.