The charity, which fights for the rights of children across the globe, has approached agencies directly with a brief to redesign the site (www.savethechildren.org).
The winning agency will also be asked to stream live footage from the charity's various projects across the globe to the site, in order to encourage consumers to donate money.
The footage will show first-hand what the public's contributions can achieve. It is also understood that the site will form the central focus of the planned ad push, which is due to launch next year.
Last month, Save the Children ended its search for a media agency by hiring Carat to handle its £3 million media planning and buying task.
Partners Andrews Aldridge and Wieden & Kennedy were also signed at the beginning of the year to handle its direct marketing and above-the-line advertising respectively.
The hunt for a digital shop follows the appointment of Adrian Lovett as the charity's director of campaigns and communications in June.