Indian Telecom authorities, namely the Department of Telecommunication, function in a reckless manner.
To this day, they have not arrived at a decent telephone numbering model. Every few years the number of digits in telephone number have changed - from 5 digits to 6 digits to 7 digits and finally 8 digits. The prefixing numbers changed to accomodate private telecom players who started providing fixed line telephone connection over the last few years.
The STD code, a very inefficient coding system currently prevalent in India - the code could be anywhere from 2 digits (leaving out the beginning 0) to upto 5 digits is a total mess. And suddenly the STD code changes when the DoT and BSNL decide that some telecom circles are merged. This is happening now to Chennai's surrounding districts like Kanchipuram, Chengalpattu, Thiruvallur etc. They are all being merged with Chennai's telecom circle. No doubt this is a good news to customers in terms of lower tariff, but the cost to the businesses is huge. About 6 four-digit STD codes are changing to 44. And all the telephone numbers in these locations are changing too - to 8 digit numbers.
Now, going forward, the mess will be even greater. Bharti and Tata Indicom were both offered numbers starting in 5 (BSNL 2, Reliance 3). Now, Bharti is going to be offered numbers starting from 4 and Tata 6. This mess will result in massive costs for the telecom operators as well as their customers.
The USA numbering system is pretty neat and there has been no change in its numbering policies drastically over the last several decades! What prevents India from adapting something similar? The cost will be one off. All area codes are uniform and of 3 digits. Then, the phone number is 7 digits.
A country with such a massive teledensity as USA has not needed 8 digit telephone numbers. But then, there is only one basic operator for a given local area. But India has now allowed multiple operators in each local area. So one could introduce the differentiating 8th digit (the first digit - 2 for BSNL, 3 for Reliance and so on). However, for the sake of uniformity, we should also look at all area codes to be of 3 digits and all phone numbers to be of 1+7 digits.
The current system of 2 to 5 digits for area codes (which will change randomly!) and anywhere from 5 to 8 digits for the telephone numbers will create large scale confusion and massive costs to customers and operators in the long run.
The mobile numbering system is also awful, whereas US has not had to come up with some unique numbering system model for the mobile phones. (UK had a different kind of numbering system though.)
India has to also overhaul the toll-free numbering system (and the premium call rate system) which have numbers suspiciously similar to an ISD call to USA (numbers go as 1-600-xxx-yyyy !!!)
Will someone please tell Dayanidhi Maran to look into this?