Klaviyo is the better SMS platform for most Australian Shopify stores, because its texts run inside the same automated flows as its emails. Mailchimp allows one text per abandoned cart, sent within 48 hours (Mailchimp, 2026). Both charge 4 credits for an Australian text, so the real difference is what each platform lets those texts do.
Mailchimp still suits a store that sends a few texts a month and wants no extra paperwork. Its Australian texts come from a virtual long number, which is a phone number, so the ACMA Sender ID Register does not apply. Klaviyo's default is a branded sender ID, and since 1 July 2026 that name must be registered through Klaviyo before you can text Australian customers (Klaviyo Help Center, October 2026).
This guide compares the two on Australian availability, cost, automation and the sender ID rules, using each platform's own help pages as they stood on 29 October 2026. Elinix AI is a Klaviyo partner and builds Klaviyo accounts for clients, so weigh our verdict with that in mind. Every point about Mailchimp links to Mailchimp's own documentation.
Key facts
- Klaviyo and Mailchimp both charge 4 credits for one SMS to an Australian number (Klaviyo and Mailchimp help pages, 2025 and 2026)
- Mailchimp allows 1 SMS per abandoned cart, sent within 48 hours of the shopper entering the flow (Mailchimp, 2026)
- SMS flows made up 7.6% of SMS sends but 45.2% of SMS revenue across more than 183,000 Klaviyo customers (Klaviyo, 2026)
- Unregistered sender IDs have shown as "Unverified" on Australian phones since 1 July 2026 (ACMA, 2026)
- By the end of March 2026, 2,761 organisations had registered 3,648 sender IDs (ACMA, August 2026)
- Klaviyo's free plan includes US$5 of mobile messages a month (Klaviyo pricing, October 2026)
How do Klaviyo and Mailchimp compare for SMS at a glance?
Klaviyo and Mailchimp both send marketing texts to Australian numbers, and both charge 4 credits per message. Klaviyo builds SMS into its flows and segments with no per-cart text limit for Australia in its help pages. Mailchimp sells SMS as an approved add-on, sends from a phone number, and caps abandoned cart texts at one.
| SMS feature in Australia | Klaviyo | Mailchimp |
|---|---|---|
| Australian SMS supported | Yes | Yes, as an add-on on Essentials or higher |
| Credits per Australian SMS | 4 | 4 |
| Sender shown on the phone | Your brand name (default), or a long number on a paid SMS plan | A virtual long number |
| ACMA sender ID registration | Needed for a brand name, through Klaviyo, 7 to 10 business days | Not needed for a phone number |
| Abandoned cart texts | Built into the flow alongside email | 1 text per cart, within 48 hours |
| MMS (picture messages) to Australia | Yes, on a long number | No |
| Before your first send | Sender ID registration or number verification | Application and approval |
Sources: Klaviyo SMS availability, Klaviyo credit rates, Mailchimp SMS marketing and Mailchimp SMS credits, all checked 29 October 2026.
If you are still choosing an email platform as well, our Klaviyo vs Mailchimp comparison for Australian ecommerce covers pricing, Shopify integration and segmentation. This guide stays on SMS.
Can you send SMS to Australian customers on both platforms?
Yes. Klaviyo and Mailchimp both support marketing texts to Australian (+61) numbers. Klaviyo lets you collect SMS consent and text Australian customers once your sender is registered or verified. Mailchimp requires the Essentials plan or higher, an SMS add-on and an approved application before your first text goes out.
Klaviyo. Australia is one of the countries Klaviyo supports for SMS. You can send from a branded sender ID, which shows your store name, or from a long code, which is a normal-looking mobile number. The long code is only available on a paid SMS plan and takes 1 to 3 business days to verify. Short codes are not available in Australia (Klaviyo Help Center).
Mailchimp. Mailchimp lists Australia among its SMS countries, with a virtual long number (VLN) as the sending number. SMS is an add-on for the Essentials plan or higher, and you must submit an application and be approved before sending. Picture messages (MMS) are limited to the US and Canada (Mailchimp Help).
The two-way question matters more than it looks. A branded sender ID cannot receive replies, so a customer who texts back "what size?" reaches nobody. If you want customers to reply, you need a number, either Klaviyo's long code or Mailchimp's VLN.
What does SMS cost on Klaviyo vs Mailchimp in Australia?
One SMS to an Australian number costs 4 credits on Klaviyo and 4 credits on Mailchimp. Neither platform publishes a fixed Australian dollar price per text. Both bill in monthly allowances that do not roll over, and both charge extra credits for long messages that split into more than one segment.
Klaviyo lists Australia at 4 credits per SMS and 15 credits per MMS in its credit table, and tells you to use your account's own values if they differ. Accounts moved to per-message pricing see the cost in their billing currency. Unused plan spend does not roll over to the next month (Klaviyo Help Center, updated September 2025). The free plan includes US$5 of mobile messages a month, which Klaviyo notes is region dependent (Klaviyo pricing).
Mailchimp charges 4 credits per Australian SMS. You pick a monthly credit amount when you apply, it is charged once you are approved, and credits bought mid-cycle cost full price. Unused credits are forfeited at the start of each billing cycle (Mailchimp SMS credits).
Two costs catch stores out on both platforms:
- Long messages. A text over 160 standard characters, or 70 characters if it contains an emoji or other Unicode symbol, splits into extra segments and uses extra credits.
- Unused allowance. Credits you do not send this month are gone, so buy for your real sending plan, not your hopeful one.
Both platforms price in US dollars, so your card is charged the Australian dollar amount on the day. For what a full email and SMS programme costs once setup and management are added, see our email marketing pricing guide for Australian ecommerce.
Which platform runs better SMS automations?
Klaviyo runs better SMS automations for a Shopify store, because a text can sit at any step of an email flow and branch on what the shopper has done. Mailchimp's abandoned cart flow allows one text per cart, sent within 48 hours. That one text can still recover sales, but there is no room for a second nudge.
Mailchimp's rules for abandoned cart texts are strict. You must ask for abandoned cart texting on your SMS application, keep double opt-in turned on for the connected audience, and send no more than 1 SMS per cart within 48 hours of the shopper entering the flow (Mailchimp Help). On the Essentials plan, flows are limited to 4 steps (Mailchimp pricing).
Klaviyo also recommends one abandoned cart text within 48 hours, but that rule is written for US recipients, where carrier rules require it. Its help page sets no such cap for other countries, and it keeps quiet hours on by default so texts do not land overnight (Klaviyo Help Center). In practice, one well-timed text after the first cart email is usually the right call in Australia too. The difference is that the choice is yours.
Flows are where SMS earns its keep. Across more than 183,000 Klaviyo customers, SMS flows were 7.6% of SMS sends but produced 45.2% of SMS revenue. Flow texts drew click rates near 10%, almost double campaign texts (Klaviyo SMS benchmarks, 2026). These are Klaviyo's own figures, so treat them as a guide, not an independent study.
Here is what happened for one client. An Australian beauty brand on Shopify had Elinix AI build its Klaviyo email and SMS system over 30 days. Compared with the previous 30 days, email reached 53% of total store revenue, and flows produced 63% of that email revenue, measured in Klaviyo and Shopify. That is one store over one month, and it is no forecast for yours. Our guide to the core Klaviyo flows for Shopify stores shows where texts fit in each one.
Free audit: not sure whether your flows need texts, or which ones? Book a free audit and we will map where SMS would earn its credits in your account.
We build these email and SMS flows in Klaviyo for Australian stores through our email and SMS marketing service.
How does the ACMA Sender ID Register affect Klaviyo and Mailchimp?
Since 1 July 2026, any business texting Australians under a brand name must register that sender ID through its message provider. Unregistered names show as "Unverified" and are grouped with scam texts. On Klaviyo, the default branded sender ID needs registration through Klaviyo. Mailchimp's Australian texts come from a phone number, which needs no registration.
The ACMA rule is simple. If you send texts with a sender ID, you register it with your telco or message provider. If you do not, your messages may show as "Unverified" in the same thread as other unverified senders, including scams. If you send from a phone number, the ACMA says you do not need to do anything (ACMA).
Plenty of businesses have already done it. By the end of March 2026, 2,761 organisations had registered 3,648 sender IDs, and 123 telcos had been approved to take part (ACMA, January to March 2026 report).
On Klaviyo, the rules are firmer than the ACMA's wording suggests. Klaviyo blocks sends to Australian recipients from an unregistered branded sender ID. You must register through Klaviyo even if you registered the same name with another provider, and new senders should not send any SMS, including welcome texts, until registration succeeds (Klaviyo Help Center, October 2026).
What the Klaviyo registration needs:
- Your ABN or ACN, and a full, current ASIC company extract listing your officeholders.
- Photo ID from a company officer, or a signed letter of authority for someone else.
- Proof you own the name, such as a domain or trademark, if it differs from your business name.
- A use case, a sample message of 160 characters or fewer, and your expected monthly volume.
Registration takes 7 to 10 business days, and Klaviyo cannot speed it up. The sender ID itself must be 2 to 11 characters and match your registered business name, company name, trademark or domain (ACMA).
Every marketing text in Australia, on either platform, must also meet the Spam Act 2003. That means consent first, your business name in the message, and a working way to opt out. Our step-by-step guide to email marketing in Australia covers consent in more detail.
Which should your store choose for SMS: Klaviyo or Mailchimp?
Choose Klaviyo if you run a Shopify store and want texts working inside your abandoned cart, welcome and post-purchase flows. Choose Mailchimp if you already use it for email, send a handful of texts a month, and want to text from a phone number with no sender ID paperwork. Either way, the per-text cost in Australia is the same.
Klaviyo suits you if:
- Your store runs on Shopify and email already drives a real share of sales
- You want more than one touch after an abandoned cart
- You want your brand name on the text, and can spend 7 to 10 business days on registration
Mailchimp suits you if:
- You are on Mailchimp Essentials or higher for email and do not plan to move
- Your texts are occasional, such as a sale launch or a restock alert
- You would rather send from a number than register a sender ID
One honest caution. Moving platforms to get SMS rarely makes sense on its own. If your email flows are thin, fix those first. For the beauty brand above, flows produced 63% of email revenue, and texts add most when they support flows that already work. Our guide to the basics of ecommerce email marketing is a good place to start.
With Black Friday close, a registered sender ID is worth sorting this week. Our Black Friday email calendar for Australian Shopify brands shows where texts fit in the sale-week sends.
Free audit: want a second opinion on your email and SMS set-up? Book a free audit and we will show you what is working and what to fix first.
If you would rather hand the build over, see how our email and SMS marketing service sets up Klaviyo for Australian Shopify stores.
Frequently Asked Questions
Is Klaviyo SMS cheaper than Mailchimp SMS in Australia?
No, the per-text cost is the same. Both Klaviyo and Mailchimp charge 4 credits for one SMS to an Australian number. Neither publishes a fixed Australian dollar price per text, and both bill in US dollars. The bigger cost difference is which email plan you need underneath, so compare the whole bill.
Can Mailchimp send SMS in Australia?
Yes. Mailchimp lists Australia as an SMS country and sends from a virtual long number. SMS is an add-on for the Essentials plan or higher, and Mailchimp must approve your application before you send. Picture messages (MMS) are not available to Australian numbers on Mailchimp.
Do I need to register a sender ID to use Klaviyo SMS in Australia?
Only if you text under your brand name, which is Klaviyo's default. Since 1 July 2026, Klaviyo blocks Australian sends from an unregistered branded sender ID, and registration takes 7 to 10 business days. Sending from a Klaviyo long code, available on paid SMS plans, needs verification of 1 to 3 business days instead.
How many abandoned cart texts can I send on Mailchimp?
One. Mailchimp allows 1 SMS per abandoned cart, and it must be sent within 48 hours of the shopper entering the flow. You also need to request abandoned cart texting on your SMS application and keep double opt-in turned on for your connected audience.
Can customers reply to my texts?
Only if you send from a number. A branded sender ID, which shows your store name, cannot receive replies. Klaviyo's long code and Mailchimp's virtual long number can. If customers often have sizing or delivery questions, sending from a number gives them a way to ask.
What happens if my sender ID is not registered?
Your texts show as "Unverified" on Australian phones and land in one thread with other unverified senders, including scam texts. On Klaviyo, sends from an unregistered branded sender ID to Australian numbers are blocked outright. Register through your SMS provider before your next campaign.
