A method of achieving co-acting services in a data system that includes telephone or data services and at least two computer systems. A transaction database connected to each computer contains transactions that are identified by transaction references, where each transaction is part of a data program for executing a service. Fetching of transactions for execution in the data system is initiated in response to an incoming call from a telephone or from an external computer. The call includes an identification of the caller and type of call. All instructions from one computer system to another takes place through the agency of the transactions, wherein certain transaction references identify transactions that upon execution transfer the service to a computer system other than the call-receiving computer system for execution. Caller information is transferred together with the transfer of the service.