A system and method for providing overflow on demand in a telecommunications network. The network includes at least one originating call location (0), at least one terminating call location (T1, T2) that subscribes to an overflow on demand service, a data access point (DAP) (102), and at least one switch (104). When a caller at the originating location (0) places a call to a chosen call terminating call location (T1, T2), the call is routed to that location via the switch (104) under DAP (102) control. Under certain circumstances, the caller can cause overflow processing to occur by merely pressing the '*' key, on a telephone keypad. Overflow processing typically includes routing the call to an overflow call terminating location (T1, T2) specified in the call processing plan for the chosen location.