Retail telecommunications in Guam is extremely competitive thanks to the presence of a large contingent of American soldiers and airmen stationed on the island. Japanese-owned Docomo Pacific has the greatest market share, providing Internet via fibre, fixed lines, cable tv plant, and cellular towers. Guam's incumbent GTA offers fibre, DSL, and mobile Internet to another 30% of the population. Smaller operators IT&E and iConnect also operate mobile networks and offer fast wireless data services. Both Docomo Pacific and IT&E have cable systems connecting Guam to the Commonwealth of the Northern Marianas. Specialist carrier PDS operates as a competitive local exchange carrier, targeting enterprise and government customers in Guam and Hawaii.

Guam is at the centre of the Pacific when it comes to cable landings, and has been there for more than a hundred years. Many cables land and cross-connect without providing significant value to the local market. Some, like ATISA, the Guam-Marianas Cable, and HANTRU1 feed other islands traffic into Guam. For local use, the Asia America Gateway Cable is used by most providers for transit to Hawaii and California, and Tata's TGN-Pacific for transit to the US Northwest. Lack of interconnections is not for lack of domestic fibre - separate fibre optic networks are operated on the island by Docomo Pacific, GTA Teleguam, IT&E, and PDS.

The SEA-US consortium cable is Guam's latest cable to the mainland of the US. From 2017 it has connected Indonesia & The Philippines to California. It's the first of a number of cable projects led by RTI, who have since connected Australia to Japan via Guam. They have planned diverse routes to the US mainland via a direct Los Angeles to Guam cable, and a loop connecting Los Angeles via Hong Kong.