Why are the limits for §7520 rates 0.2% to 30%
When you see 30% returned for the §7520 rate, that is because there is no rate data for the transfer date entered. In most instances, this will be a “future” calculation. The user would enter a rational number for the §7520 rate. The IRS provides tables for calculations with the §7520 rate between 0.2% and 20%. The rates have never reached 20%, and only recently dipped below 1%. The 30% is an indicator to the user that they need to use their own rate (or that there is a problem with the AFR File as mentioned in the first 2 FAQs).