Free Tool

SUI Penalty & Interest Calculator

Calculate the penalty and interest on a state unemployment insurance underpayment. Select your state, enter the principal amount and days past due.

How SUI Penalties and Interest Work

When an employer underpays state unemployment insurance contributions — whether from a rate error, a missed payment, or a payroll discrepancy — the state agency assesses a penalty on the principal amount plus interest that accrues monthly from the due date.

Penalty rates typically range from 5% to 15% of the principal, assessed once. Interest accrues monthly, typically at 0.33% to 1.33% per month depending on state. The combination of a flat penalty plus compounding interest means that small underpayments grow significantly if left unresolved.

Ohio's SUI interest rate is lower than average at 0.33% per month (4% annually), while states like California, Texas, Illinois, Michigan, New York, and Wisconsin charge higher rates. California charges 15% penalty plus approximately 1.08% monthly interest.

Kreto catches rate errors before they become penalty notices.

Upload your SUI rate notice for free. Kreto verifies the math against your payroll data and flags any discrepancy before the protest window closes.

Upload Free Notice →