A guide to SMS Sender ID

We receive more questions about the SMS sender ID than anything else.

This short guide answers all the main questions that you may have have along with examples of what can and can’t be done with it.

Let’s start with the basics…

What is an SMS sender ID?

The SMS sender ID is the text display name that you see at the top of your phone’s screen and is used to identify who sent the message. The SMS sender ID is simply who a text message is from.

It’s also known as the originator or sometimes the sent address.

 

 

The SMS Sender ID for this text is Hermes

What is the maximum length for an SMS sender ID?

If the SMS sender ID is alphanumeric, the maximum number of characters permitted is 11. If the sender ID is set as a numeric value, allowing the recipient to reply, then the maximum permitted number of digits is 15.

So there are two different sender ID maximum lengths, depending on whether you are using letters or numbers.

Why is there such a small limit on the number of characters permitted in a sender ID?

This is simply one of the SMS standards that has always been the case.

When SMS began, way back in 1992, the sender ID was set at 11 characters and has remained as the standard since then. 

Back then, screen sizes were comparatively tiny, so it may not have been possible to fit more than 11 characters on all phone models.

Can you reply to a message if the sender ID contains letters?

If you set the sender ID to letters, recipients will not be able to reply to the text. (See example below where a message send was attempted and the sender ID of the incoming text was JohnLewis.)

So you have a choice. You can set the sender ID to letters, in which case you cannot reply to the message. Alternatively, you can set the sender ID as a reply number, allowing replies to be sent.

 

 

You cannot reply to a text with an alphanumeric sender ID

Can the SMS sender ID contain spaces?

The sender ID can only contain letters or numbers, spaces are not permitted.

No other non-GSM characters are permitted either. So no dashes or other imaginative ways to create visual interest! Unicode characters are not permitted.

Can the SMS sender ID contain a mixture of letters and numbers?

A sender ID can contain both letters and numbers. See below for an example SMS sender ID that contains both letters and numbers – Test1234. If numbers and letters are used, the maximum character limit is 11

Different countries and networks set their own rules on how much control they allow in setting the SMS sender ID.

 

 

SMS sender ID showing letters and numbers

Can the sender SMS sender ID be spoofed?

In many countries the sender ID can be set to whatever the sender wishes. This means that there is a danger that a fraudster could attempt to impersonate an organisation or individual.

There have been many illegal smishing campaigns that attempt to convince consumers to visit fake websites and enter their account details. (Smishing is similar to email phishing except the fraud is attempted over SMS.)

SMS smishing fraudsters will often use the sender ID to convince the recipient that the message is from a legitimate source.

Alarmingly if someone sends a text from a sender ID that is already a contact in your phone, rather than just displaying the digits of the number set, the person’s name will be displayed.

The message will also appear in the message thread, making it appear even more genuine.

The example below shows a spoofed sender ID as ‘Graham’.

 

 

Spoofed SMS sender ID

Country restrictions on setting the SMS sender ID?

The ability to set the sender ID depends on which country you are sending to. In the UK, you have complete control over what you set it as, but not every ID is permitted (see below). In many countries including the US, the networks do not permit you to send messages from a custom sender.

All messages must come from either a local long code (that looks like a normal mobile number) or from a short code.

Each country and network has its own rules on what is permitted. 

If you attempt to send a message with a customised sender ID to a country or network that does not permit them, then the sender ID will usually be replaced with a local long code or the message may fail to be delivered.

Restrictions on setting the sending ID as virtual mobile number when testing internationally

Also be aware that sometimes you cannot reply to a message if the sender ID is a virtual mobile registered in a different country from which you are texting.
Let’s explain that.

So if you have an Irish virtual mobile number, (starting 353) and you set that as the sender ID and send a message to UK mobile number (44), the message will arrive without any issues.

The user however will not be able to reply to the text. Virtual mobile number often will only receive texts from mobile numbers registered in the same country.

Results are inconsistent and you need to make sure that you test thoroughly.

Restricted sender ID in the UK

Can I change the sender ID on a personal text?

No, with P2P SMS, you don’t have the ability to change the sender ID. The sender ID is automatically set  to the mobile number of the person sending the message.

If that mobile number is stored in the recipient’s phone then the sender ID will be displayed as the contact name that was set when the contact was stored.

How do I send a message with a company name as the sender ID?

The first thing to mention is that you can’t change the sender ID from your own mobile phone.

You’ll need to use a third party SMS provider in order to change the sender ID to something other than your phone number.

Choose a business SMS provider that allows you to control the sender ID.

We suggest choosing a company that’s based where you are. They will be far more familiar with local rules and regulations for changing the originator.

Almost all SMS providers offer a free trial with some free credits so you can test the SMS sender ID before making any commitment.

Whether you’re using a web based software platform or an SMS API to send your messages, the sender ID will be one of the parameters that you can control.

A few SMS providers charge for the ability to set the sender ID but most provide this free of charge.

Can I set my own mobile number as the sender ID?

Yes you can. As long as there are no sender ID restrictions in the country in which you mobile is registered, you can set your own mobile number as the sender ID.

When you do this, the sender ID will display whatever name you have selected in your phone’s settings.

Many countries have restrictions on what sender ID can be used. These are covered in the next section.

Country and network restrictions on setting the sender ID

Bear in mind that different countries and networks have different rules on setting the originator.

Some countries restrict setting the SMS sender ID or require you to register the sender ID in advance of being able to send messages.

The registration process can be slow, ranging from a day or 2 to 3 months plus.

Some countries don’t even allow you to set the sender ID at all, most notably the US, where the sender has to be set as a numeric local number.

As recently as August 2022, Australia has brought in new rules requiring you to register sender IDs before you’re allowed to use them in SMS campaigns

Why do countries restrict the sender ID of texts?

These restrictions are an attempt to reduce SMS fraud and phishing attacks.

Having the ability to set the originator to anything you wish allows fraudsters to send texts pretending to come from legitimate sources such as banks, delivery companies, government departments etc.

They then use the increased credibility to convince people to complete forms on illegal websites or send in additional personal information that could leave users vulnerable to fraud.

It’s all very shady and depressing.

List of key markets that have SMS sender ID restrictions

Please note that this list includes selected countries not all countries that have restrictions with the sender ID.

If you’re a customer of The SMS Works you can see all the sender IDs that you have been using our SMS insights tool.

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