What is an SMS grey route?

Why should buyers of business SMS care?

If you could send SMS to your customers for an incredibly cheap rate, but with the knowledge that the content and contacts would not be secure; messages would be delivered slowly, and some messages might not get delivered at all, would you be tempted? Yes or no, it’s really important that you make an informed decision, and that’s what this page sets out to help you with.

What is grey routing?

Grey routing is a very cheap way of sending bulk SMS which exploits a vulnerability of mobile phone networks.

In order to allow individuals to use their mobiles when travelling, networks such as O2, Vodafone etc. allow overseas networks to pass messages originating in their countries over to the UK, either for an agreed fee, or, if the overall message volume is low, for free.

Ordinarily, if you are sending a message from the UK to a UK handset, the message will go straight to the UK mobile network. But, by sending your message to a remote foreign country’s network first – say, Afghanistan or the Solomon Islands – and then back to the UK, you could reduce the cost of sending that message to almost nothing.

When used for high volume business SMS, this practice is called ‘grey routing’.

Is grey routing illegal?

Technically, no, it’s not illegal. However, the agreement to allow messages to pass freely between foreign networks was set up to allow individuals to use their phones overseas, not to make it cheaper for businesses to send messages to their customers.

The mobile phone networks have specific channels set up for business SMS (also called A2P) which ensure fast, reliable and secure delivery of messages to the recipient’s handsets. They also mean that the network is properly compensated for sending the message.

What are the risks of sending messages through grey routes?

Simply, you risk the security of your messages (both the content and the recipients’ details), as these can be intercepted, copied and even altered; the speed in which your messages will be delivered is likely to be slower; there is a possibility that your messages will not be delivered at all, as the mobile phone networks are increasingly finding ways to shut grey routes down.

What can the mobile phone networks do to prevent the use of grey routes?

By 2020, it’s estimated that 50% of mobile phone networks will have implemented software that identifies when grey routes are being used, and shuts them down (it’s currently 15%). It’s a complex operation as obviously they don’t want to shut down personal SMS, but the software solutions available are increasingly able to swiftly identify business traffic and stop them.

How can I tell if my messages are going through grey routes?

The first indication is the price you are paying for your SMS to be sent. If it’s much lower than other pricing you’ve seen or been quoted, there is a good chance the saving comes from the messages being grey routed.

Ask your SMS service provider if they use ‘direct connections’ – which is to say, they send messages straight to the local mobile phone networks – as this is the only way to be 100% sure that the messages are not being grey routed.

Also look at the speed in which messages are delivered – most SMS service providers have a free trial which should allow you to determine how quickly messages are delivered to handsets.

Would you like to know more?

We’ve written a guide to grey routing, which goes into more detail about what’s meant by direct connections, the role of aggregators, why this is such a hot topic for the mobile phone networks , and some interesting data on attitudes to grey routing in different countries.