DoT has reportedly amended the National Numbering Plan 2003 for migration to an 11-digit numbering plan in mobile services by prefixing the number '9' to the existing two-digit PLMN Access Code.
While some reports say that the extra number would be a 9, others suggest that the new numbers will be starting with 8.
The new numbering plan is likely to be implemented in Jan 2010.
TRAI numbers show that there were 415 million cellular subscribers at the end of May 2009 compared to 277 million in May 2008, accounting for a 50 per cent growth.
The 2003 numbering plan allowing 10-digit number was formulated based on forecast of 50 per cent teledensity by 2030. However, with India adding 10 to 14 million mobile subscribers each month, the wireless subscriber base has already crossed 500 million prompting the authorities to take this step.