15th December 2010 onwards, all mobile operators in Malaysia will start to offer 3+8 numbers for new mobile numbers. These includes both Postpaid and Prepaid package, while availablity of 3+8 number for prepaid may take some time later. This new number format will have 8-digits subscriber unique numbers and a standard prefix of 011 which will be shared across all operators. The reason of this implementation by SKMM (Suruhanjaya Komunikasi dan Multimedia Malaysia) is we have run out of 7-digit numbers, which show a high demand on mobiles in Malaysia.
It will only affect new customers or registrations. Existing customers with 3+7 number will remain with their numbers and there are no plans yet to make changes. However, you still can register 3+7 number if it is available. There will be no problem to receive and make calls between 3+7 and 3+8 numbers since most modern phones already supported for this feature.
The three major mobile operators have set up FAQs regarding this new implementation, check out on Celcom, Maxis and DiGi if you need more details. For mobile application developers, maybe you should check out your app whether it can support for the new number formats. Just in case for technical glitch or bugs.