The US is going through a phase of change in the telecom circle after the implementation of WNP. Subscribers are shifting providers to gain maximum benefits, but the current trends show slow shifting by customers. The infrastructure availability both in terms of hardware and software for WNP is coming in place slowly. A few problems were reported because of heavy load when NP came into effect. This is now changing and the US might have a complete portable environment in 2004.

The FCC mandate for number portability includes a few restrictions and a time-line for implementation. Briefly, subscribers with billing addresses in the top 100 US population centers (called MSAs) were to be able to take their numbers with them after 24 November 2003. People in the rest of the US have this freedom after 24 May 2004. Since wireless carriers are not required to wait until the deadline, many will allow number portability even before the deadline.