The agency is the first place to go to after logging in. It'll generate nice amounts of TF$ all the time that needs to be collected before the storage gets filled. As your fame level increases (based on your Battle Points), you'll get more TF$ per hour. Upgrading the agency will increase the storage size, allowing you to store more TF$ before you need to collect it, which is very important in order to take full advantage of collecting money while you are not playing.
Agency Upgrades Edit
|Building Level||Upgrade Price||Upgrade Time||Maximum Paycheck|
|5||Max Level||Max Level||12000|