How does interest on the city bank investment work?

The City Bank is a time-deposit investment: money is locked for a chosen period of 1 week, 2 weeks, 1 month, 2 months or 3 months and earns interest at that period's APR^[1]. Each period has its own APR, which changes over time and is shown in the bank when investing.

How it works

• The wiki describes the Bank as the long-term investment bank where players safely store money and gain interest in a time-deposit style^[1].
• Five periods exist: 1 week, 2 weeks, 1 month, 2 months and 3 months. New players must complete one period to unlock the next^[1].
• Once the period is up, the money can stay in the bank until the player withdraws it^[1].
• Each period has its own APR, and each varies independently, so the best period changes over time. A 2020 player guide said 2 months was best then and 3 months a couple of months earlier; that is a dated player report.
• A March 2025 player guide gave an example: $2 billion for 1 month at 10% APR pays about $16.67 million. It gave APRs of about 5-10% and a limit of up to $2 billion, or $3 billion with a 10-star Oil Rig. Treat these as player-reported figures.
• Money is locked during the investment and protected from theft. No early withdrawal option is documented; a 2015 suggestion of a cancel button was never shown to be implemented.

What raises the rate

• Each Bank Interest merit adds 5% to bank interest. The wiki says it applies from the next investment, not the current one.
• Holding 1.5 million shares of Torn City Investment Banking (TCB) improves rates by 10%, with merits taken into account, per the wiki's stock page. Bug's 2018 guide said the same: a 10% increase in interest, calculated after merits^[2].
• The June 2019 update raised natural APRs; the target APR with full merits and the stock stayed about the same.
• A 2026 beginner guide lists Bank Interest as a merit choice after Education Length and Crime Progression, only if you are actively investing money. That is one author's opinion, and the author calls the order a long debate^[3].

Alternative: Cayman Islands

The same 2025 player guide describes the Cayman Islands offshore bank: interest is paid monthly on the lowest balance that month, at a base 0.5% per month and a maximum of 0.675%. Money can be withdrawn without waiting for a period, but it requires travel.

Older rate tables no longer apply. The wiki's stock page still shows base rates of 1%, 2%, 8%, 22% and 40% in its TCB example. The 2019 update replaced that scheme with per-period APRs.

Where sources disagree

• The wiki's TCB example uses old base rates of 1% to 40%, while a 2025 player guide gives APRs of about 5-10%; the 2019 update replaced the old scheme.^[2]