The value of the Army's Recruiting Partnering Project (RPP) has not so far been disclosed.
As well as supplying the Army's RPP system and support, Capita is also expected to supply the "enabling technology" for a similar system to the Royal Navy and the Royal Air Force.
The MoD expects to officially award a contract in mid March 2012, once the procurement process is fully complete and has been approved by government ministers.
The MoD said the RPP is an initiative to "meet both the quantity and quality of recruits required for the Army's current and future needs". The MoD said the RPP will "modernise army recruiting and deliver significant savings to the taxpayer over ten years".
Capita is said to have won the contract against competition from both Serco and Logica, in a selction process that began in 2009. To complete the work Capita is expected to put together a consortium of different suppliers, which will include advertising agency JWT.