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Will we run out of mobile numbers?

How many mobile numbers are there?

There are around 8 billion mobile subscriptions worldwide as of 2021. The total number of available mobile numbers depends on the numbering plan used in each country. Most countries use a 10-digit numbering system, which allows for 10 billion possible numbers (from 0000 00000000 to 9999 999999). However, not all of these numbers are allocated for mobile use.

The pool of available numbers also differs by country and region. For example, the North American Numbering Plan has around 800 million assignable numbers. Some countries like China and India have over 1 billion mobile subscribers already, but still have enough unused numbers thanks to their large populations and numbering plans.

So in summary, there are billions or even trillions of possible mobile numbers globally thanks to the capacity of 10-digit numbering systems. But the availability of unused numbers depends on each country’s specific allocation and usage.

How are mobile numbers assigned?

Mobile numbers are assigned and managed by national regulatory authorities in blocks to mobile operators. For example, Ofcom in the UK and the FCC in the US oversee number allocation.

The regulators assign blocks of million numbers, usually in the format 0XX XXXX XXXX. The mobile operators can then issue numbers from their allocated blocks to customers.

So while there may be billions of possible numbers, they are rationed carefully by regulators to avoid wasting this limited resource. Operators bid for or are allocated only the number of blocks they need for their subscriber base.

This centralized allocation by regulators is important for managing the availability of numbers. It ensures operators efficiently utilize their share of the numbering space.

Are we running out of new mobile numbers?

Some countries are running low on new available numbers in existing 10-digit blocks, especially densely populated ones like India and China. But there are a few mitigating factors:

– Number recycling – Disconnected and inactive numbers are recycled back into the pool of available numbers. This expands the usable life of existing numbering blocks.

– New blocks – Regulators can allocate new blocks with different prefixes to operators to expand the numbering range. For example, India added 9XXX prefixes in 2015 when existing blocks were nearly exhausted.

– Number portability – Allows changing operators without changing numbers. Reduces repeat allocation of same number.

– 11-digit numbering – Some countries like Argentina have switched to 11-digit numbers to increase numbering capacity. But this requires expensive network upgrades.

– 4G Mobile – Upgrades to 4G mobile technology are more spectrally efficient. They allow operators to support more numbers using the same spectrum frequencies.

Number Pooling

Many countries now use number pooling to optimize allocation. It reduces wasted numbers by sharing blocks among operators. For example, Ofcom in the UK introduced number pooling in 1999.

Earlier, each operator received allocated blocks starting with 077, 078, etc. This left unused gaps if subscriber numbers didn’t reach block capacity.

With pooling, Ofcom allocates numbers from shared blocks without pre-assigned prefixes. This allows continuous allocation and reduces wastage.

Forecast of mobile numbering requirements

Here is a forecast of mobile numbering requirements over the next 5 years:

Year Projected New Mobile Subscriptions (Millions) Projected Additional Numbers Required (Millions)
2023 1250 1100
2024 1200 1050
2025 1100 950
2026 1000 900
2027 950 800

Key assumptions:
– Global mobile subscribers to reach 6.5 billion by 2027
– Accounting for number recycling and multiple SIM card users

This shows an additional 4.8 billion numbers may be required over next 5 years globally. But the actual numbering capacity is significantly higher, so exhaustion is unlikely.

Strategies to increase number capacity

If existing 10-digit numbers ever do near exhaustion, there are a few strategies countries can use:

11-digit numbering

Adding an extra digit increases the numbering capacity 10-fold. This offers billions of new number blocks, but requires major infrastructure upgrades.

New prefixes

Allocating new prefixes like 9XXX expands the pool. India added several new prefixes in recent years after existing ones were nearly used up.

Number recycling

Better detection and recycling of unused and disconnected numbers improves utilization of existing blocks. Mandating minimum use levels also prevents operator hoarding.

VoIP numbers

Using VoIP technology, virtual numbers can be assigned without geographic restrictions. This increases potential capacity without new physical numbering resources.


While mobile subscriptions continue to grow globally, numbering exhaustion is not an imminent risk thanks to the large capacity of 10-digit systems and effective numbering management by regulators.

New prefixes, number recycling, VoIP adoption and upgrades to 11-digit systems can all help tackle localized shortages if required. But with current techniques like pooling, most countries have enough numbering space for many years, if not decades.

Regulators also continue to monitor usage and allocate additional resources well in time to meet demand. So it’s unlikely we’ll run out of mobile numbers anytime soon.