Under TISA, what must be consistent in how interest is calculated?

The correct answer highlights the requirement for consistency in the method used to determine the required minimum balance for earning interest. Under the Truth in Savings Act (TISA), financial institutions are obliged to provide clear and detailed disclosures regarding how interest is calculated, including the minimum balance necessary to earn that interest. This consistency ensures that consumers can accurately compare different accounts and make informed decisions based on how interest rates will apply to their balances.

Furthermore, having a standardized method for calculating the required minimum balance is crucial for transparency and consumer protection. It allows consumers to avoid unexpected fees or loss of interest due to fluctuating account balances.

In contrast, promotional rates may vary and do not need to maintain consistency in their application since they are typically temporary offers. The location of disclosure statements and the timing of when disclosures are provided also do not directly pertain to the method of interest calculation itself but rather to how the information is communicated to consumers. Thus, the emphasis on a consistent method for minimum balance requirements is a core principle of the TISA, aimed at ensuring fairness and clarity in savings account offerings.