The bank has said it had retained the Dentsu-owned agency following a review carried out in line with its standard procurement process. The account includes both online and offline media as well as retail and B2B activity.
Carat pitched alongside its sister agency and search specialist iProspect.
Previously Carat handled all the above-the-line media as well as digital display and paid search. Alongside iProspect it will now also manage SEO.
The review kicked off in May and was originally tabled to be complete by the end of September. It actually concluded last Friday (4 October). Carat’s new contract, for 2014 and 2015, starts on 1 January.
Keith Moor, the director of brand and communications at Santander, oversaw the process.
Moor said: "We are looking forward to continuing our now long standing working partnership with Carat. We would like to thank both MediaCom and Carat for their hard work and extraordinary commitment during the lengthy and rigorous process."
Santander UK last reviewed its media planning and buying in 2011, when it retained Carat after OMD pulled out of the process before the final round. The final round of the 2011 process was believed to be a closed online auction.