This feature automatically amends the dialled digit-string of an outgoing exchange call to route the call via a preferred carrier. The modification performed is determined by the digits dialled, the time-of-day and the day-of-the-week. Toll restriction is applied to LCR calls. LCR digit-modifications are transparent to toll restriction. There is a (non-changeable) 8-second delay between the time the last digit is dialled by the user and the LCR begins to redial the number. If the calling extension has SMDR output, the dialled number is shown as-dialled, without any digit-modification that may have been introduced by the LCR tables.