Klaviyo migration services

Migrating to Klaviyo means moving data and behaviour

An email marketing migration does not end with importing contacts. You also need to transfer which messages people receive, why they enter a sequence, when they leave and what the team needs to keep operating. Copying the database alone can leave automations, exclusions and forms disconnected.

Start with the reason for switching: a missing integration, limitations in the current system, difficulty managing journeys or a need to centralise work. This separates what must be preserved from what should be redesigned. Your Klaviyo ecommerce setup should address those specific needs.

Scope the accounts, stores, languages, channels and owners. Agree which history must be retained and identify the source platform’s limitations. Do not promise that every field will move with the same meaning before checking what can be exported and represented at the destination.

Build an inventory before setting the changeover date

Review the current system with the people using it. Go beyond prominent campaigns: examine forms, segments, exclusions, automations, templates, integrations, store notifications and manual processes. Identify who depends on each item and what would happen if it stopped working.

This minimum inventory turns migration work into verifiable deliverables. Add configuration references and a decision for each item: retain, rebuild, retire or investigate.

The inventory also informs project cost and scope. An account with a few templates and several custom integrations may require more work than one with many messages based on the same design.

Map fields and states before importing

Create a source-to-destination mapping. Record each field’s name, meaning, format, example and intended use. Two fields called “purchase date” may describe different things: the last order on a profile or the date of a specific event.

Klaviyo documents import routes and a procedure for bringing in historical unsubscribes. Preserve those exclusions: possession of an email address does not establish an active subscription.

Define which source prevails when records conflict and how exceptions will be investigated. Do not resolve a state conflict by automatically choosing the value that permits sending. Keep unresolved cases out of sends until their position is verified.

Test a small sample first, including difficult cases: incomplete data, different languages, repeated addresses and different states. Check dates, empty values and special characters. Matching the total record count does not demonstrate a correct mapping.

For example, a fictional store’s language field contains both “es” and “Español”. The plan might normalise these to one value, retain the original for traceability and set unknown values aside for review. Make that decision before the field determines an email’s language.

Rebuild journeys around their actual rules

For every email automation, document the entry event, conditions, delays and exit reasons. Decide what happens to people already inside the old system. Starting everyone again at the first message may repeat communications; ignoring them may leave follow-up unfinished.

Do not assume that identical event names imply identical data. Inspect a recent store case and the fields the message needs. Product blocks, cart links and purchase conditions must use information actually reaching the destination.

When migrating from Mailchimp, dynamic template tags need adaptation, including the unsubscribe tag. Copying HTML alone does not preserve its behaviour in Klaviyo.

Decide which system owns each message during transition. Include notifications sent directly by the store, so the team knows which remain and which are replaced. Preparing a new journey does not authorise two live versions at once.

Keep content decisions alongside technical ones. If message order changes or an old offer is removed, record why and who approves it. That distinguishes deliberate improvements from migration errors.

Acceptance tests before the first production send

Klaviyo supports previews using profile or event data where applicable. Rendering tests do not cover every live-send behaviour; also validate test journeys and their links.

The following matrix describes outcomes to agree with the team. Use controlled test contacts rather than enabling communications to the full database to check a rule.

Approval should identify the version tested. If an event, condition or template changes afterwards, review which tests are invalidated and repeat them before enabling that part.

Plan the changeover and a possible rollback

The launch plan should name who performs each step, who reviews it and which signal requires stopping. Agree a change window with time to check signups, purchases and sending. Avoid combining migration with a major campaign when the team cannot handle incidents.

Temporary coexistence can help verify data, but sending ownership must be clear. Define what pauses at source, what activates at destination and how changes between export and final cutover are reconciled. Include new unsubscribes from that interval.

Prepare a workable rollback before starting: which configuration can be restored, which data needs reconciliation and who authorises it. Stopping the new system does not mean automatically reactivating every old message. Review activity already completed to avoid repetitions.

Include deliverability here: domains, authentication, initial audience and monitoring. Technical migration and send assessment are related, but a successful import does not demonstrate that the channel operates as intended.

How to determine that the migration is finished

Reconcile source and destination by relevant categories, rather than total profile count alone. Explain duplicates, excluded records, errors and data that could not be moved. Retain the reconciliation report with the original inventory and approved decisions.

Do not remove old access before saving agreed reports and configurations. Review temporary integrations and credentials once no longer needed. Retirement should leave a clear owner for routine operations and outstanding issues.

• Contacts, exclusions and fields checked through counts and samples.
• New signups and store events verified at destination.
• Enabled journeys with approved acceptance tests.
• One sending owner for each migrated message.
• Templates, links, preferences and personalisation verified.
• Previous reports retained with their definitions.
• Documentation, access and monitoring handed over to the team.

After changeover, compare metrics using compatible periods and definitions. A new attribution model can change reports without creating additional sales. Migration is complete when the team can operate, verify and explain the new system, rather than when a file finishes uploading.

Sources and further reading

• Klaviyo · Migrating subscribers and unsubscribes
• Klaviyo · Migrating from Mailchimp
• Klaviyo · Preview and test emails