Customers will be able to review their monthly expenditure using Egg's spend analyser, then load up their remaining spending money for the month into the Egg Money account.
It will offer 1% cashback for purchases made using the account, but charge 6.9% APR on money borrowed.
Egg Money is the company's biggest product launch since it introduced the Egg Card six years ago. It follows the Egg Money Manager product in 2004, which allows customers to manage all their banking arrangements in one place. It is hoping Egg Money will bolster its reputation for innovation.
Press and online activity to promote Egg Money starts this week. It will be followed by a TV campaign, created by Mother, in November.
Claydon Heeley Jones Mason will develop press and direct-response activity, while Agency Republic will create a digital campaign to support the launch.
Prudential withdrew Egg from sale last year after failing to attract a suitable bid.
Egg had 3.6m customers in July. Its pre-tax profits rose to £15m in the six months to 30 June, against a loss of £1.7m a year ago.
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