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Rather unhelpfully, the definition of the term SMS grey route is a little er… grey.

Essentially it refers to low quality, back door SMS routes that are not sanctioned by the mobile phone operators.

Messages are routed via third party countries rather than being piped directly to the Networks in the UK.

These Trojan horse messages are trying to disguise themselves as personal SMS traffic which makes it quite difficult for the networks to police.

Grey routes avoid the Interconnect fee

Mobile phone networks charge each other for delivering texts on their networks.

So imagine you’re on an EE contract and you’re sending a text to a friend who’s on Vodafone.

Vodafone will charge EE for delivering the message onto your friend’s mobile.

So far so simple

If a sly business SMS provider or SMS /text aggregator can find a way of avoiding this fee, then it’ll be able to offer temptingly low rates to its customers.

The interconnect free routes can be accessed by targeting SMS access points where no formal arrangements between operators exist.

There are dozens of these available at any one time. Large volumes of SMS can be dumped onto the network without having to pay a bean in operator fees.

All very cunning but somewhat shady.

Billions in lost revenue

This interconnect fees amounts to an estimated  $55 billions of revenue for the networks and represents one of the core cash flows for their SMS services.

Industry experts estimate that the lost revenue from using grey routes could be be as high as $15 billion.

The scale of the issue is just staggering, with Brian D’Arcy from Anam Technologies commenting,

Brian D'arcy - Annan Technology

I can say this with confidence, every operator in the world today is carrying A2P traffic and not all are charging for it.
Brian D’arcy – Annam Technologies

(For non-industry people, A2P means Application to Person. When a text is sent from an app or piece of software to an individual.)

Perry Offer from Dialogue Communications was less guarded,

 Our view is that over 75% of global mobile operators have done nothing about that and they basically have this revenue hole.
Perry Offer – Dialogue Communications

Low price – high risk

So what’s wrong with using SMS grey routes? Well it’s a simple case of you get what you pay for. Grey routes are notoriously unreliable.

Speaking at a roundtable in London, Hugh Spear of Dialogue said,

Taking the grey route to bypass operator charges increases the chances of non-delivery, provides a safe, profitable haven for the spammers, and risks damaging brand reputation for the brands associated with the messages and the operators themselves.

Hugh Spear – Dialogue Communications


 5 reasons why you’ll regret using SMS grey routes

1. Delays

There’s a horribly real possibility that SMS sent via grey routes might be subject to the most agonising delays. Messages could be arriving hours after they were submitted, potentially in the middle of the night. Ouch.

2. No Delivery Reports

SMS grey routes often do not support delivery reports. If delivery reports are available, they are likely to be either patchy or inaccurate.

3. No Sender ID

Rather than a message being sent from a company or brand, messages via grey routes do not often allow you to set who the message is from.

Often a random number will appear as the sender ID – giving perhaps not the most professional impression.

4. Unsupported Characters

If your message contained any non-standard characters like accents or currency symbols, these are likely to be replaced with 3 or 4 seemingly random characters.

5. Long Messages not permitted

If you’re using a tier 1 connection (a route which pipes directly to the UK networks), then you can increase your message length to over and above the standard 160 characters.

The messages lands on the phone as one text, just as it would if you were sending from one phone to another.

Using SMS grey routes, your message will land as a series of texts, with the real possibility that the second part arrives before the first.

Is it illegal to use SMS grey routes?

No using an SMS grey route is not illegal.
The networks allow SMS traffic to flow freely between the networks so that individuals can communicate with their contacts wherever they happen to be. 

It’s this loose arrangement between mobile networks that grey route traffic exploits. Business (or A2P) SMS is supposed to be routed through specific channels which ensure delivery is fast and efficient.

Clogging consumer routes with vast volumes of business SMS is unethical and costs the mobile industry billions of dollars in lost revenue every year.

What are the networks doing to stop SMS grey traffic?

With so much as stake, global mobile networks are keen to stop the use of grey routes and they are making significant progress In doing just that.

They’ve been busily installing SMS firewalls which are now becoming very effective at stemming the flow of SMS grey traffic.

Analysts at Mobilesquared estimate that by 2022, 83% of mobile network operators will have deployed A2P firewalls. This should result in the global grey route market dropping by almost 50%.

SMS grey route traffic will fall from $1.4 billion to just $750 million by the end of 2022.
By the same time, SMS grey traffic will account for just 3% of all A2P traffic.

Another dodgy option – SIM farms

SIm farm for SMS spamming

These were fairly prominent a few years ago but thankfully they seem to have quietly sunk back into the mud.

Sim farms are even more unethical than using grey routes. 

Here’s how they work.

Sim farms exploit the generous text bundles that are available to consumers on monthly mobile phone contracts.

Typically, a consumer contract will have up to say 3000 free texts as a monthly allowance.

By installing the SIM for that contract into a reader, it’s possible to send out thousands of texts from that mobile number.

A whole rack or ‘farm’ of sims can merrily send out texts until the monthly allowance has been used up.

It potentially allows massive volume of texts to be sent at virtually no cost. You may remember several years ago being plagued by endless spam offers from payday loan or ambulance chasing companies.

These companies were big users of these sim farms. You could at one point even buy the equipment to set up your own sim farm, reducing the cost even further. Maybe you still can.

It’s pretty shady to say the least. The networks throw considerable resource at trying to identify when a single number appears to be sending the same message to thousands of recipients.

The advice must be to avoid this option at all costs.

Roll the Dice

Some users will feel that despite the risks of an SMS campaign going badly wrong, the cost saving of using grey routes or sim farms are still worth it.

For most, the risks to brand and reputation are simply too high.

As business SMS prices have reduced over the past decade, so the costs saving argument has become less compelling.

The SMS Works only uses direct, tier one connections for sending all its SMS API traffic. We never use grey or indirect routes.

ICO logo

Users of business SMS services should always be aware of the rules regarding SMS campaigns as set out by the Information Commissioner’s Office. The rules are there to protect consumers and make perfect sense.

The ICO has increasing power to dish out hefty fines to transgressors and has been largely responsible for the massive decline in SMS spam.  

According to their website, they are currently investigating over 175 companies.

So where do we go from here?

For most of us the grey route option just simply isn’t worth it. The benefits of using tier one routes massively outstrip the marginal price saving.

Feel free to set up a free SMS API account with The SMS Works. It take just a minute or so and you’ll receive 50 free text credits for testing.

This is normally plenty, but please let us know if you need more. Have a quick look at our SMS integration guides which will help you get up and running in no time.

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The Editorial Team The SMS Works