Electronic payments in the UK will now be processed in a matter of hours rather than days as the new UK Faster Payments Scheme takes effect.

Previously, payments initiated between UK banks over telephone and online banking took at least three working days to process.

UK payments association Apacs said that 13 banks and building societies have already signed up to the new service.

Other financial institutions will be able to join in the future, either as members or by accessing the system through agency arrangements with a member just as they do with other payment systems.

The Faster Payments Scheme will run alongside existing systems in the UK such as Bacs and Chaps, and is being rolled out using a phased approach to help ensure that the service is launched smoothly and securely.

The system was originally due to be launched in November 2007, and will be limited to electronic transactions of up to £10,000.

However, the scheme has caused consternation among many IT security firms which have warned that it could be major boon for fraudsters who will be to whisk money out of infiltrated bank accounts in the blink of an eye.

Deloitte & Touche has suggested that the system represents a significant challenge for banks in the fight against crime as they will have far less time to spot unusual or suspicious transactions.

Elizabeth Sipiere, banking managing director at IT services group Microgen, warned that banks must ensure that they still retain control and visibility of transaction processing.

"The UK Faster Payments Service is the biggest change in consumer payments since the introduction of the direct debit," she said.

"Given present market conditions faster payments will be welcomed by consumers and businesses, but it is vital that it is introduced without teething problems.

"It is imperative that banks have the right processes and safeguards in place to support the initiative."

Mark Dunleavy, financial services manager at data integration firm Informatica, also warned that banks must ensure that data is up-to-date and accurate.

"Financial services may be an increasingly automated world, but banks have traditionally thrown human resource at problem areas," he said.

"The timescales associated with the UK Faster Payments Scheme means that this is no longer possible.

"UK consumers have been craving faster transaction times for a number of years, but delivering on this is no small challenge for banks.

"Data will make or break their efforts to comply with the initiative as in order to complete the transaction quickly they need to be able to integrate data from multiple systems. Data accuracy and access is absolutely critical."