The deal will run for three years and IBR won the contract after a three-way pitch. IBR will also be sole UK supplier of Centrica's corporate accommodation booking services. Centrica brands include British Gas, the AA, Goldfish and One.
"The key reason why companies such as Centrica use our services is to consolidate its spend and is a way of making their lives easier," said IBR account manager Louise Kenrick. "The group appointed us because we offer a range of services that will be used by Centrica in the future."
Centrica travel manager Oliver Beloch added: "We expect to make significant savings as a direct result of this new partnership."