In a new research brief, "Account Aggregation", Datamonitor forecasts that by 2005, there will be 121 million online banking customers in Western Europe and the US, with almost half using account aggregation.

The consumer appeal rests on the convenience of being able to manage different financial relationships from a single Web page through PCs, mobile phones and wireless devices, reports Datamonitor. Access to the service will enable customers to transact online between several accounts, regardless of how many banks these are spread over. Customers will be able to make online bill payments, transact between accounts and to check portfolio performance.

Banks are set to be the key beneficiaries of the account aggregation wave, according to the report. Those that can deploy a robust, secure and reliable service are in an ideal position to lever existing customers for increased cross- and up-sell opportunities resulting from aggregated consumer data from all the users' accounts and a deeper personalised relationship between bank and consumer. The analyst firm estimates the majority of growth will occur between now and mid-2003.

While the majority of aggregation services are based around an outsourced model, there will be an increasing push by banks to move the development and deployment of aggregation services inhouse. As more non-financial services firms such as utility companies, Web-portals and other lifestyle sites jump onto the aggregation bandwagon, banks will feel the squeeze as consumers source aggregation services from portal-type sites that have strong brand, vast consumer bases and sticky product offerings.