This guide sets out how to run that migration for a large Australian list. It draws on the published outcomes of our Meriton Suites migration, which moved more than 1 million contacts from Marketing Cloud to Klaviyo, and on Klaviyo's own migration documentation. It covers what the integration does and doesn't move, how to keep Spam Act consent records intact, how to avoid paying for contacts you shouldn't migrate, and how to warm and cut over without hurting deliverability.
Why do Australian brands move from Marketing Cloud to Klaviyo?
The usual reason is speed. Marketing Cloud is a broad enterprise suite, and many teams find that building a segment or journey depends on a developer or a SQL query. Klaviyo is built around a single customer profile, ecommerce events and self-service segmentation, so marketers can build and launch more of it themselves.
That was the brief at Meriton Suites, Australia's largest operator of apartment-style hotel accommodation. Its existing platform was limiting the speed and precision of campaigns across more than 1 million customer records. It needed advanced segmentation, real-time targeting and integration with its ecommerce shop front and booking systems. The published outcome: campaigns tailored by guest type, location and booking behaviour, and a 4x increase in campaign execution speed and segmentation capability.
Klaviyo isn't the right answer for every Marketing Cloud customer. If your marketing runs on deep Sales Cloud or Service Cloud data, complex B2B journeys or Marketing Cloud's advertising and personalisation add-ons, compare the total change before deciding. Our Salesforce Marketing Cloud practice and Klaviyo practice work on both sides of that decision.
What does Klaviyo's Marketing Cloud integration move, and what doesn't it?
Klaviyo has a native Salesforce Marketing Cloud integration built for migrations. According to its migration guide (updated 18 November 2025), you connect it with a Marketing Cloud user that has web services (API) access, plus your account's WSDL link for the SOAP API. Klaviyo strongly recommends turning on the option to collect open and click data.
| Data | Moved by the integration? | What to plan |
|---|---|---|
| Lists and their subscribers | Yes. Lists appear in Klaviyo with their members. | Decide which lists are worth keeping. You can sync specific lists only. |
| Unsubscribes, bounces, held and deleted contacts | Yes. Contacts with these statuses are globally suppressed in Klaviyo. | Check suppression counts match before any send. |
| Engagement history | Partly. Up to 180 days of Received, Opened and Clicked Email events, then new data every 5 minutes. | Export older history yourself if you need it for reporting or segmentation. |
| Data extension attributes (preferences, loyalty tier, location, booking history) | Not covered in Klaviyo's guide. | Export and import by CSV or API, mapped to Klaviyo profile properties. |
| Consent evidence (source, date, wording) | Not covered. | Keep the original records and import consent status deliberately (next section). |
| Journeys, automations and templates | No. | Rebuild as Klaviyo flows and templates. |
Klaviyo advises against running both platforms side by side except during the transition. Plan a fixed overlap window, not an open-ended one. Every week of dual running is a week where an unsubscribe in one tool must reach the other.
How do you keep consent and unsubscribes intact under the Spam Act?
Treat consent as the part of the migration you can't redo. The ACMA's spam guidance says you must have consent before sending marketing email, whoever does the sending, and that it's up to you to prove it. For express consent, it asks you to keep a record of who gave consent, when and how. Every commercial message must also honour an unsubscribe within 5 working days, and the unsubscribe option must keep working for at least 30 days after you send.
In practice, that gives a migration four rules:
- Suppressions land before subscribers. The integration suppresses unsubscribed and bounced contacts automatically. If you also import contacts by CSV, upload any historic unsubscribes and bounces to Klaviyo's suppression list first. Klaviyo's guide to migrating subscribers and unsubscribes covers this.
- Import consent per contact, not per file. Klaviyo's list import guide (updated 30 March 2026) supports a consent column per channel. A blank cell means "never subscribed", so a contact with no recorded opt-in won't be marked as consented by accident. Klaviyo warns that backdated consent timestamps may be skipped when resubscribing, so keep the original evidence outside Klaviyo too.
- Keep the evidence trail. Archive the Marketing Cloud consent fields, sign-up source and timestamps in a store you control before the old contract ends. If the ACMA or a customer asks, that is your proof.
- Close the dual-running gap. During the overlap, sync unsubscribes between both platforms at least daily. Five working days is a legal maximum, not a target.
Check inferred consent too. The ACMA says inferred consent needs an ongoing relationship and marketing directly related to it, and doesn't cover messages sent just because someone bought something. A migration is a good moment to find contacts whose consent basis is unclear and stop emailing them.
Should you migrate all 1 million contacts?
Usually not. Klaviyo bills by active profiles: any profile that can be emailed counts, and suppressed profiles don't count toward your plan, according to its active profile guide. Importing years of dormant addresses raises your bill from day one and drags down engagement while you are trying to warm a new domain.
Before you migrate, sort the list into three groups:
- Engaged: opened or clicked recently, or subscribed recently. These seed your warming segments.
- Lapsed but consented: no engagement for months. Import them but keep them out of campaigns until a win-back or sunset flow has run. Klaviyo suggests running a sunset flow first, then suppressing those who don't respond.
- Not worth moving: hard bounces, role addresses, contacts with no clear consent basis and records you have no reason to keep. Australian Privacy Principle 11 obliges you to destroy or de-identify personal information you no longer need, so a migration is a natural point to apply your retention policy (see the OAIC's APP quick reference).
Plan the file mechanics too. Klaviyo asks for CSV files of 50 MB or less, and an import can take a couple of hours. A million rows with a dozen attributes will often exceed that limit, so split files by segment or region and reconcile the counts after each load. Turn off list-triggered flows before you import, or every imported contact receives the welcome series.
One more question for your privacy team: where the data lives. Klaviyo's sub-processor list (updated 11 September 2026) says existing customer accounts are hosted and processed in the United States. An EU data centre is offered only to new accounts at creation, and Klaviyo's Australian entity provides support with hosting in the US. Moving Australian customer data to Klaviyo is therefore a cross-border disclosure under APP 8. Update your privacy policy and vendor assessment if needed. If you are also using customer data in automated decisions, read our guide to the Privacy Act automated decision rules that start on 10 December 2026.
How do you rebuild Marketing Cloud journeys as Klaviyo flows?
Start with an inventory, not a copy. List every Journey Builder journey and automation, its entry trigger, audience size, last send date and revenue or conversion contribution. Many large accounts carry journeys nobody owns. Retire those and rebuild the rest as flows, in order of value.
The biggest design change is the trigger. Marketing Cloud journeys often start from a data extension refreshed on a schedule. Klaviyo flows work best from real-time events: a booking, an abandoned checkout, a viewed product, a loyalty tier change. That depends on the integration work, which is where much of the value sits. At Meriton Suites, connecting the ecommerce environment to Klaviyo enabled real-time behavioural triggers, so messages respond to what a guest just did rather than last night's batch.
Map the integrations early. Klaviyo connects natively to platforms such as Shopify, BigCommerce and Magento. Booking engines, loyalty platforms, CRMs and data warehouses usually need API or middleware work, which our data integration team handles. If the same customer also lives in Salesforce, a customer data platform or a clear system-of-record rule stops profiles drifting apart. Our guide to integrating Salesforce, Atlassian, Adobe and ERP covers that wider architecture.
How long does domain warming take, and how do you cut over?
Plan on roughly two to three months from first send to full volume. Klaviyo's domain warming guide says warming is essential any time you move to a new email provider. It doesn't give a fixed duration. Instead, it ramps your audience in stages, each held for about two weeks, and only moves on while engagement holds. The first campaign should go to fewer than 10,000 recipients, and if open rates fall below 20% you pause the ramp.
| Stage | Audience | Move on when |
|---|---|---|
| 1 (about 2 weeks) | Clicked in the last 30 days, or subscribed in the last 15 | Open rate holds at 20% or higher; aim for 30% on the first send |
| 2 | Engaged in the last 60 days (up to 3 sends a week) | Open rate still at 20% or higher |
| 3 | Engaged in the last 90 days (up to 2 sends a week) | As above |
| 4 | Engaged in the last 120 days (weekly) | As above |
| 5 | Engaged in the last 180 days (monthly) | Full programme, with unengaged contacts in a sunset flow |
This is where the 180 days of imported engagement history matters. Without it, Klaviyo can't tell your engaged contacts from your dormant ones, and the first campaigns go to the wrong people. Turn on flows only when they have a record of strong performance. Klaviyo's thresholds are open rates above 40%, click rates above 1%, and unsubscribe and complaint rates below 0.1%.
A workable cutover sequence for a large list:
- Freeze new journey builds in Marketing Cloud and agree the overlap window.
- Connect the integration, sync lists, suppressions and 180 days of engagement.
- Import data extension attributes and consent by CSV, suppressions first. Reconcile counts.
- Set up and authenticate the Klaviyo sending domain.
- Rebuild high-value flows and templates and test them on internal seed lists.
- Start warming with the 30-day engaged segment while Marketing Cloud handles the rest.
- Move flows across one by one as each stage holds, syncing unsubscribes daily.
- Switch off Marketing Cloud sends, archive consent evidence and close the account at renewal.
Frequently asked questions
Does Klaviyo's integration copy Marketing Cloud data extensions?
Klaviyo's migration guide covers lists, subscribers, suppressions and engagement metrics, not data extensions. Plan to export the attributes you need and import them as profile properties by CSV or API.
Can we keep using Marketing Cloud for transactional email?
Yes, for a defined period. Klaviyo recommends against running both platforms beyond the transition. If transactional email stays on Marketing Cloud, document which platform sends what and keep unsubscribes in sync.
Does the migration need a privacy impact assessment?
Often it's worth one. You are moving personal information to a new overseas-hosted processor, changing how it's used for segmentation, and possibly deleting records. Ask your privacy officer whether your APP 8 and APP 11 obligations need updating.
Plan your Marketing Cloud to Klaviyo migration
Great Minds is a Klaviyo Gold Advisor partner and Salesforce consultancy based in Sydney. We have moved more than 1 million contacts from Marketing Cloud to Klaviyo for Meriton Suites, with consent, engagement history and segmentation attributes preserved. For a broader view of how marketing data fits with your other platforms, see our list of agentic AI use cases by department, including marketing.
If you are weighing a move, book a migration consult with our team. We'll size your list, map your journeys and consent records, and give you a cutover plan and timeline before your next Marketing Cloud renewal.
