Do you need to register SMS sender IDs to send business SMS messages to UK mobile numbers?

No, there’s no requirement to register SMS sender IDs before you can send SMS messages to UK mobile phone numbers.

Unlike many countries, the UK has fairly light touch regulations for business SMS, which means companies can quickly start using A2P SMS without getting bogged down in admin.

There’s a lot of confusion on this subject as many providers, mainly US based, are stating on their websites that registering sending ID is required, when it is not.

Google’s Gemini AI tool generated an answer that is completely incorrect.

Their AI overview was also wrong.

The reason for the misinformation on the topic is that a few US providers incorrectly state that you need to register sender IDs.

I’m not entirely sure why they get this so wrong. It might be that they want to align their onboarding process across territories, so apply the same admin load for all countries.

Or it could be that they’re just not familiar with the regulations in the UK.

What are the rules for using sender IDs in the UK?

SMS A2P users are free to use any alphanumeric sender ID they wish as long as it’s not restricted by the UK mobile networks. (There’s a maximum of 11 characters or 15 numeric characters.)

There is a large list of restricted sender IDS that users may not use. The list includes many banks and financial institutions as well as major high street and well known brands.

These sender IDs are restricted to help prevent fraud, where criminals impersonate brands and attempt to direct users to fraudulent websites.

The list of restricted sender IDs is obviously not published as it would allow criminals to bypass the restricted sender IDS but still attempt their scams.

The Mobile Ecosystem Forum (MEF), a mobile industry body, runs a service called the SMS Sender ID protection Registry. This initiative informs registered organisations with all the existing and newly restricted sender IDs.

It’s a great way of keeping the SMS industry informed of new sender IDs that fraudsters have attempted to use dishonestly.

What happens if I try to send a text with a restricted Sender ID?

If you send a message with a restricted sender ID, then your text will simply not be delivered.
We always recommend testing your messages before using them in a live environment.

As long as you’re not doing anything that could be interpreted as suspicious, then you are unlikely to encounter any issue with deliverability.

BT / EE have additional sender ID restrictions

BT / EE have brought out their own rules for sender IDs that they have applied to messages being delivered on their network.

Generic sender IDs like Bank or Banking have been banned. They have however published the list of Sender Ids that can no longer be used.

We’ve published an article that provides more detail on the BT/EE sender ID restrictions.

You do not need to register SMS sender IDs in the UK
There are restricted sender IDs that will cause messages to fail if used. (This list is not published.)
BT/ EE have their own list of forbidden Sender Ids that they have released.
You can use a numeric sender ID if you want to receive replies.