California Irrevocable Standby Letter of Credit (SLOC) is an irrevocable promise from a bank or financial institution to pay a specified sum of money to a beneficiary on behalf of the issuer if certain conditions are met. A California SLOC is typically used to guarantee payment in the event of a breach of contract or default on a loan. This type of letter of credit is common in commercial transactions, as it allows the issuer to guarantee payment without having to rely on the performance of the counterparty. There are two types of California Irrevocable Standby Letters of Credit: a non-revolving SLOC and a revolving SLOC. A non-revolving SLOC is a one-time credit line that is drawn down when a specified event occurs. A revolving SLOC is a credit line that can be repeatedly drawn down over a specified period of time. Both types of Slots require the issuer to provide the beneficiary with written notice of any changes or cancellations.