For tax purposes, in California, SUI stands for State Unemployment Insurance and SDI stands for State Disability insurance, according to the State of California Employment Development Department. In 2014, the CA SUI tax rate is Schedule F+. Employers are taxed between 1.5 percent and 6.2 percent on each employee's income up to $7,000. The 2014 CA SDI tax rate is 1 percent on income up to $101,636; the maximum withholding is $1,016.36 per employee.
Symmetry Software's Payroll Taxes website notes that the CA SUI tax rate does not include a mandatory Employee Training Fund contribution of 0.10 percent of up to $7,000 of income per employee. According to the State of California Employment Development Department, new employers for 2014 are assigned a 3.4 percent SUI tax rate for two to three years. The exception is if someone purchases an existing business with employees. In that case, the new owner may elect to retain the previous owner's SUI tax rate.
Wikipedia notes that the California SDI program has been in place since 1946 and pays employees who are temporarily disabled a weekly benefit amount equal to 55 percent of their average weekly pay. SDI benefits are only available to employees who paid SDI taxes or have self-employment coverage. For an employee to receive SUI benefits, the person must be unemployed through no fault of his own and meet minimum wage and weekly eligibility requirements, according to the State of California Employment Development Department.