omer wants to get a single bill that details usage for all the subscribed services. For the customer this single bill is easier to track, maintain, and pay. Convergent billing for a package of services is currently offered by most service providers. Ease of understanding: There would be multiple items under a single service for which the customer gets charged. For example, in a simple call service a different rate is applied for interstate call, intercountry calls and international calls. Also special charges are applied for calling specific service numbers. In the first bill from a service provider, in addition to the rate wise breakdown OSS/BSS Functions there would be charges against initial provisioning, equipment supplied, service charges, and SO on. Now, how complex would the bill be for the case when the segregation of charges for a package of services is provided in a single bill. The billing information should be presented to the customer in a format that is easy to understand and helpdesk/online/call support should be offered to customers for clarifying bill related queries. Multimode, multipayment, and multiparty options: In multimode billing, the billing system must be capable of handling "real-time or nonreal-time" billing of "single or batch" billing records. Multipayment option, also known as unified accounting gives the customer the ability to do payment using postpay, prepay, nowpay, or combination of these payment options. The mul- tiparty settlement option gives a customer the flexibility to settle multiple bills related to the customer or multiple bills incurred by multiple parties. For example, all bills associated to different members in a family can be linked to a single payee. This leads to ease in payment of bills. It should be kept in mind that the billing system in service provider space should have the required capabilities to offer multipayment and multiparty options to the customer. Billing system should have carrier-grade performance: Current billing systems have to support complex 