The main business cost is the expenditure related to the unit consultation and investigation. Such as: data fees, telephone fees, service fees, salaries of consultants and investigators, etc.

this main business is up to the company itself to decide which part is the main business, and then the related costs of which part are the main business costs. For example, computer information technology services, company exhibitions and conference services are all main businesses, so these three related costs are all main business costs, which can be divided into three sub-accounts.

since the service industry has no tangible objects to sell like commodities, there is generally no main business cost, so the main business cost of the service industry can be zero. Travel expenses, wages, rent, etc. are expense items, not cost items. The entries are: debit: related expenses; Loan: cash or bank deposit or accounts payable.