NTT DoCoMo Inc. and KDDI Corp. will begin a free recorded message service to give out a subscriber's new telephone number when the person switches to their services.
But DoCoMo, the i-mode service provider, and KDDI, the au service provider, will not provide messages, left at customers' old telephone numbers, when their subscribers defect to another company, a decision that is drawing complaints from many mobile phone users.
The new program stems from a government proposal to allow a mobile phone user to continue using the same phone number after switching service providers.
This system would probably encourage mobile users to shop around more if their providers are not meeting their demands, industry officials said.
The message service will be provided for 90 days from the day mobile users cancel their former subscription contracts.