The five UK mobile network operators all participate in mast sharing arrangements with each other and with other companies such as Arqiva, which owns a number of sites.
Planning Policy Guidance Note 8: Telecommunications makes clear that applicants for new masts should provide evidence that they have explored the possibility of erecting antennas on an existing building, mast or other structure and that such evidence should accompany any prior approval or planning application made to the local planning authority. If the evidence regarding the consideration of sharing existing masts and sites is not considered satisfactory, the planning authority, or the Secretary of State on appeal, may be justified in refusing prior approval or planning permission for the development. Site sharing may not always be possible or the most appropriate environmental solution in every case. The ability to site share may be limited by a range of possible factors including the extent of the coverage required, topographical features and reception interference issues.
The mobile operators have established a computer program which monitors site-share usage and is used for making site-share requests between each other.