With the introduction of number portability between telephone service providers on 1 March 2000 and the introduction of the closed numbering plan on 29 March 2002, the Federal Communications Commission (ComCom) established the necessary foundations for geographical number portability. Since April 2002, therefore, providers have been able to allow their customers to retain their telephone number throughout Switzerland when they move house. Since April 2002, these customers have also had the possibility of being allocated any Swiss fixed network number regardless of their place of residence, on condition that their provider supports this. Internet telephony providers in particular have grasped this opportunity and have offered their customers corresponding products. The traditional fixed network providers, however, initially offered geographical number portability only to a limited extent.

Since provision of geographical number portability is voluntary, providers are also free to impose a processing charge for this service. If a provider does not support telephone number porting or if it does not provide connections at the new address, customers are free to take their old telephone number with them to a different provider.

In practice it has become apparent that so far customers have been hesitant to avail themselves of the possibility of taking their telephone number with them when they move house. However, OFCOM assumes that in the future this will happen more and more and that the population will not longer consider it strange for someone to have a telephone number which does not match the region where they live.