Most states have usury laws (usually statutes) governing the amount of interest that can be charged on a loan. Usury laws vary from state to state, but the elements of a usury claim are generally: (1) a loan of money; (2) an absolute obligation to repay the principal; and (3) the exaction of a greater compensation than allowed by law for the use of the money by the borrower.

And interest means compensation for the use, forbearance, or detention of money. The term does not include time price differential, regardless of how it is denominated. The term does not include compensation or other amounts that are determined or stated by law not to constitute interest, or that are permitted to be contracted for, charged, or received in addition to interest in connection with an extension of credit.

Service charges, finance charges, and discount points are generally considered interest for purposes of usury. But contingent or uncertain charges are generally not considered interest.

In South Dakota, usury laws are codified to regulate the maximum interest rates that can be charged on loans. The usury laws in South Dakota stipulate that the legal maximum rate of interest for money due or owing under any contract is 12% per annum unless a different rate is contracted for in writing, in which case any rate of interest may be agreed to (SDCL 54-3-16). However, there are exceptions to this general rule, particularly for regulated lenders such as banks, savings and loans, credit unions, and certain licensed lenders who may charge higher rates as permitted by other specific provisions of state law or federal law. The elements of a usury claim in South Dakota would include the existence of a loan of money, an absolute obligation to repay the principal, and the charging of an interest rate exceeding the maximum allowed by law. The term 'interest' in South Dakota encompasses compensation for the use or forbearance of money, but does not include certain charges like time price differentials that are not deemed interest by law. Service charges and finance charges are typically considered interest for the purposes of usury unless they fall into categories that the law specifically excludes from the definition of interest or allows in addition to interest.