Compare UK and Australian SMS sending numbers

Last updated at:

You will learn

Please note that only account Owners and Admins will have the ability to add/manage sending numbers.

Learn about sending numbers for the UK and Australia, including what each can do and who can use them. 

Overview of features


Branded sender ID

Long code

Short code (vanity)

Available countries






Plan needed

Free & paid




$0, included in all plans

$0, included in paid plans



Base throughput

10 mps

10 mps

100 mps

Can receive SMS

Double opt-in

Click-to-text forms


SMS conversations (two-way messaging)


Branded sender IDs

Branded sender IDs (also known as alphanumeric IDs) are the default option in Klaviyo for both the UK and Australia. The same brand ID can be used in both countries. 

A branded sender ID is best for your business if branding is important to you. This sending ID can be customized to fit your brand, so recipients always know who their messages are coming from.

The downside of this ID is that it cannot receive messages, so your recipients cannot text you back. This means that you cannot use the following Klaviyo functionality with a branded sender ID:

  • Click-to-text forms and email banners
  • Subscribe keywords
  • SMS conversations/two-way messaging
  • Double opt-in
  • Mobile support

When using branded sender IDs, high-volume senders may need to request more throughput. Typically, we recommend reaching out to our Support team and asking for more throughput when you are sending more than 140,000 messages at time. 

Long codes

Long codes are able to receive inbound messages, which gives you more flexibility in what you can do with SMS. 

You will be able to use: 

  • Double opt-in
  • Click-to-text forms and email banners
  • Subscribe keywords
  • SMS conversation/two-way messaging
  • Mobile support

This allows your customers to opt-in using subscribe keywords, get 1-to-1 support, share their preferences and interests, etc.

Long codes are not branded. The number will look like any other number, and customers won’t automatically know who’s texting them. 

A long code is also only good for reaching subscribers in 1 specific country. If you have an Australian long code, you cannot use this number to send to anyone in the UK, US, or Canada. 

If you have both a long code and branded sender ID, the long code always takes precedence over the brand. For example, if you have an Australian long code and a branded sender ID, the long code will deliver your messages to AUS recipients, while the brand will send only to those in the UK. 

We recommend you request more throughput when you are sending around 140,000 messages at a time.

Short code (vanity)

Short codes are only available in the UK. However, short codes for Australia are on our product roadmap!

Short codes are best for those who are high-volume senders. For example, if you want to send campaigns to 300,000 or more recipients, a short code is likely the best sending number for you. On the other hand, if you are mainly sending SMS via flows or through smaller, more segmented campaigns, a long code or brand ID is likely better. 

Not all businesses and industries are eligible for a short code. You must apply and be approved. This approval process takes several weeks, so even if you are eligible, you cannot instantly start sending from a short code. 

Short codes are only good for reaching subscribers in 1 specific country. If you have a short code for the UK, you cannot use the same short code in Australia, Canada, or the US. 

Additional resources

Was this article helpful?
2 out of 2 found this helpful