[1] In 39/38 BC, Antonius appointed him to the office of monetalis in one of the eastern provinces of the Roman Empire, during which time he minted coins with Antony's and his wife Octavia's portrait.
In the year 37 BC, at a time of increased tension between Marcus Antonius and his colleague Octavianus, Fonteius Capito served as Antony's representative in Italy.
After having negotiated with Octavianus, he travelled with Gaius Maecenas, Lucius Cocceius Nerva, and a number of poets including Horace and Virgil, down to Brundisium in order to discuss the situation with Marcus Antonius and to prepare the groundwork for the Pact of Tarentum.
[2] After concluding the initial treaty negotiations, Antony sent Fonteius Capito in the autumn of 37 BC to Egypt.
Then, in 33 BC, Fonteius Capito was appointed suffect consul, a post he held from May to June of that year.