A telecommunications system includes a control point and a switching point for discounting a customer's billing for telephone calls completed in a wide area centrex/PBX network that includes an abbreviated dialing plan. The control point receives, from the switching point, a query that is generated based upon receiving a telephone call. The control point determines a call type code that is based upon a calling station type and a called station type. When the call type code is eligible for discounted billing, the control point generates a billing record of a first type for the call. The billing record of the first type is used to discount the billing for the call. The control point forwards, to the switching point, the billing record of the first type for the call. The switching point generates a billing record of a second type for the call and, when the call type code is eligible for discounted billing, the billing record of the first type is used to modify the billing record of the second type.