Broadband internet access is available to all Dorset residents, according to British Telecom.
On Wednesday BT upgraded the exchange at Powerstock, the last exchange in the county to have the high speed internet communications system installed.
About 21% of all households have already taken up the service which has cost almost £2m to put in place.
The hope is that more businesses will be encouraged to relocate to Dorset because of the service.
Ian Cambrook, of the Bournemouth, Dorset and Poole Economic Partnership, said: "Having this high-speed technology available throughout the county will prove a powerful incentive to existing businesses and new businesses considering moving to Dorset to take advantage of the superb quality of life here."