A company that hopes to link retailer loyalty offers to shoppers' credit card numbers has received a venture capital funding.

Birdback received $2.4 million from Passion Capital, Paul Nikkel, Playfair Capital, #1seed, and Luke Johnson, according to published reports. The company is a London-based startup hoping to link both in-store and online loyalty offers so that shoppers can access them without carrying physical cards. Birdback allows retailers, loyalty/voucher publishers, and advertisers to offer greater numbers of deals to customers without installing new point-of-sale devices.