Since the time I am using a mobile phone, we have always been getting a 10 Digit Mobile Number. It’s been so many years but we still have the same number of digits – 10.

Initially, the numbers started with ‘9’. Probably if you are using the same number for the last 7-8 years, you might still be having a mobile number that starts with 9.

As time passed, we got numbers starting with 8, 7 then 6. So, what is the exact reason behind these 10 digits?

**Why do we have a 10 Digit Mobile Number?**

The number of digits in a mobile number depends primarily on the population of a country. Based on that, laws are made.

The moment I am writing this blog post, the population of India is 1,315,517,078 as per livepopulation.com.

So, we have already surpassed the 10 digit population at this moment. There is no scope of making mobile numbers less than 10 digits.

It is always assumed that each and every citizen will possess a mobile phone. Therefore, India settled for 10 digit numbers under the Governmentâ€™s National Numbering Plan (NNP).

By keeping 10 digit numbers, we get a combination of **1,000 crore **numbers.

Still didn’t understand mathematics?

**How do Permutation and Combination work for making Mobile numbers?**

Let’s understand in an easier way!

Assume that you have 2 pairs of Jeans and 4 T-shirts. So, how many combinations will you get to wear?

Similarly, from 10 digit cell numbers, we have 10 billion combinations.

**10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 = 10,00,00,00,000 = 10 billion (1000 crore) subscribers!**

This number is not going to deplete so fast. However, with the rise of smart devices and every consumer using 2 SIM cards, authorities got tensed.

To exhaust these numbers slower, Government even made compulsory to make M2M mobile numbers of 13 digits which will not be operated by humans.

M2M mobile numbers mean nothing but Machine-to-Machine numbers. You don’t have to worry about 13 digit numbers, as per Times of India reports.

For example, you might be getting spam calls from various numbers where a pre-recorded tone is played. M2M mobile numbers are also used in devices like swipe machines, cars, electricity meter, IoT, etc

**Do mobile phone numbers from all countries have 10 digits in them?**

No. It is not the fact that every country will implement the same rule. As I mentioned above, it depends mainly on the population.

Some countries like Niue have 6 digit mobile numbers including the country code because that is more than enough for them.

Meanwhile, countries like China have up to 12 digit mobile numbers due to their huge population and technological advancements.

This is to say that India might get an 11 or 12 digit mobile number in the future. Let’s see.

I hope you understood why Indian Mobile numbers have 10 digits in them, and some other countries have more.

Also, you can never predict a mobile number’s location by merely looking at the number. Some country codes and actual mobile numbers might play their game well.

P2