Yes, loan companies usually contact your employer during the application process to verify both your income and the date you started working. This is necessary because even though employment information does appear on your credit report, it may be out of date or incomplete.
Most employers require verification calls to go either to their HR department or to a third-party company that provides the requested information. Less formal companies may direct these calls to the employee’s supervisor. This can cause problems for the company, though, so most require HR involvement for consistency, accuracy, and privacy reasons.