A customer specific planning tariff is only considered when routing / rating / scheduling is triggered to identify Planning Tariffs. Customer ID will be specified while Carrier ID must not be provided for these tariffs. See "Planning tariffs".
Routing / rating / scheduling requests to identify planning tariffs will consider a customer specific planning tariff where the applicable Customer ID is associated with the applicable request (when Customer ID has been specified for the Rate Quotation or when all shipments attached to the load reference the same Customer ID).