Typically, the core financial functions are included with the base package, while features like CRM and human resources management may cost extra. Some offerings are bundled by industry so, for example, a manufacturer would buy a package with supply chain management included or a retailer would buy a package with commerce included. On-premises ERP vendors typically charge an upfront per-user license, while software-as-a-service (SaaS) vendors charge on a per-user, per-month or year basis. In some cases, there are transaction-based charges.