SAP Business One is designed to fit all types of businesses. For example, usually we set the revenue accounts of a business as “Sales” accounts, but some businesses may need to put revenue accounts into other types of accounts. To resolve this situation,as of SAP Business One 9.1.we allow any account type to be selected for revenue accounts.
Go to Administration > System Initialization > Company Details > Basic Initialization tab and select “Allow Selection of Any Account Type for Revenue Accounts”.
Then you may choose any account type without being limited to “Sales”.