The review, handled by the AAR, comes as the financial services brand prepares to step up its direct communications in a bid to increase the cross-selling of products to customers.
The bank is boosting its below-the-line budget by £7 million to £42 million this year.
The bank's most popular product is its credit card, which attracted 171,000 new customers in the second quarter of 2004.
However, Egg is looking to boost sales of its other services, such as personal loans or insurance, to holders of its credit card using e-mail and direct marketing.
Egg's above-the-line account, held by Mother, is unaffected by the review.