Core banking is a banking service provided by a group of networked bank branches where customers may access their bank account and perform basic transactions from any of the member branch offices.
Core banking is often associated with retail banking and many banks treat the retail customers as their core banking customers. Businesses are usually managed via the corporate banking division of the institution. Core banking covers basic depositing and lending of money.
Core banking functions will include transaction accounts, loans, mortgages and payments. Banks make these services available across multiple channels like automated teller machines, Internet banking, mobile banking and branches.
Banking software and network technology allows a bank to centralise its record keeping and allow access from any location.
Core banking became possible with the advent of computer and telecommunication technology that allowed information to be shared between bank branches quickly and efficiently.
Before the 1970s it used to take at least a day for a transaction to reflect in the real account because each branch had their local servers, and the data from the server in each branch was sent in a batch to the servers in the data center only at the end of the day (EOD).
Over the following 30 years most banks moved to core banking applications to support their operations creating a Centralized Online Real-time Exchange (or Environment) (CORE). This meant that all the bank’s branches could access applications from centralized data centers. Deposits made were reflected immediately on the bank’s servers, and the customer could withdraw the deposited money from any of the bank’s branches.
Advancements in Internet and information technology reduced manual work in banks and increasing efficiency. Computer software is developed to perform core operations of banking like recording of transactions, passbook maintenance, interest calculations on loans and deposits, customer records, balance of payments and withdrawal. This software is installed at different branches of bank and then interconnected by means of computer networks based on telephones, satellite and the Internet.
Gartner defines a core banking system as a back-end system which processes daily banking transactions, and posts updates to accounts and other financial records. Core banking systems typically include deposit, loan and credit-processing capabilities, with interfaces to general ledger systems and reporting tools. Core banking applications are often one of the largest single expense for banks and legacy software are a major issue in terms of allocating resources. Spending on these systems is based on a combination of service-oriented architecture and supporting technologies.
Many banks implement custom applications for core banking. Others implement or customize commercial independent software vendor packages. Systems integrators like Cognizant, EdgeVerve Systems Limited, Capgemini, Accenture, IBM and Tata Consultancy Services implement these core banking packages at banks. More recently, entrants such as Temenos (late 1990’s) and Probanx (since 2000) have also provided entry level core banking systems, focusing on neobanks and electronic money institutions.
Open source Technology in core banking solution or software can help banks to maintain their productivity and profitability at the same time.
While larger financial institutions may implement their own custom core, community banks and credit unions tend to outsource their core systems to system providers. While there is no consensus or a public register on the actual Core Banking Providers, various market research companies like Gartner or Forrester Research release annual deal surveys mentioning platform deals  
- ^ Jump up to:ab “Core Banking System”. Gartner. Retrieved 14 August 2014.
- ^“Open Source Technology for Core Banking Solution & Software”. www.kimayainfotech.com. Retrieved 20 March 2018.
Ofer Abarbanel is a 25 year securities lending broker and expert who has advised many Israeli regulators, among them the Israel Tax Authority, with respect to stock loans, repurchase agreements and credit derivatives. Founder of TBIL.co STATX Fund.