Who this is for and our promise

Audience

Ecommerce managers, CRM leads and founders switching from Mailchimp, Yotpo, ActiveCampaign, Omnisend or a custom ESP to Klaviyo for Email and SMS.

Promise

Zero data loss, protected deliverability and correct transfer of both Email and SMS consent. First revenue from core flows within 7 to 14 days of go live.

When switching to Klaviyo makes sense

• Your current ESP limits ecommerce events, segmentation, reporting and innovation. Klaviyo centralizes this into a single real time customer profile.
• You want one CRM or CDP where you can see a clear customer view without external tools and act on it directly.
• You want out of the box integrations and to capture gains by consolidating your tool stack, such as Email, SMS, push, reviews and WhatsApp roll out.
• You want to manage channels centrally, such as Email, SMS, WhatsApp and app push, with provable per channel consent.
• You want to iterate faster on flows, product feeds and personalization with predictive insights and AI.

Klaviyo blog: migrate before peak season

Phase 1 — Before migration

Phase 2 — During migration

1. Safe imports including suppressions: email subscribers with properties and consent timestamps. SMS in E.164 with country and consent source. Upload unsubscribes and bounces to the suppression list first.
2. Keep imported contacts out of Welcome: set a property such as source=import and add a Flow Filter or a Conditional Split.
3. High impact flows live: Welcome, Browse, Cart and Checkout Abandonment. Test templates and personalization.
4. Warming policy: first campaign under 10,000 recipients to a 30 day engaged segment. Weeks 1 to 2 focus on 30 day. Weeks 3 to 4 expand to 60 day when indicative opens are around 20 percent. Use Guided Warming and keep cadence. Dedicated IP requires around 30 to 40 days of warming.
   Klaviyo Help: how to warm your sending domain · Klaviyo Help: guided warming · Klaviyo Help: which warming process to use
5. Re engagement on your old ESP: migrate only positive responders to keep your new reputation clean.

Phase 3 — After migration

• Finalize forms and pop ups: ensure all sign up sources point to Klaviyo such as footer, checkout, pop ups and lead ads.
• Reporting and attribution: document differences between Klaviyo and GA4, keep UTMs consistent and compare trends and segment performance.
• Hygiene and governance: run a sunset flow for long term inactive profiles and keep routines for bounces, spam and opt outs.

How-tos and examples

A) Engaged segments

Recent Engaged 30, 60 and 90: Clicked Email or Placed Order within X days. Build SMS variants when you have enough volume.

B) Welcome series for Email and SMS

• Trigger: Added to Main List excluding source=import.
• Timings: email on day 0 and day 3 to 4. SMS on day 1 to 2 if no click.
• Filters: placed order exits the flow. Caps: at most 1 message per 24 hours per channel.

C) Cart and Checkout Abandonment timing

• Email: 1 to 3 hours after the event.
• SMS: 24 to 48 hours with consent and outside quiet hours.

D) SMS migration essentials

• Export phone in E.164, Country, Consent Timestamp, Consent Source and Consent Text.
• Import via Upload list of SMS contacts. Do not add opt outs to marketing lists.
• Sender strategy: branded sender ID, long code or toll free. Coverage differs by country.
• Klaviyo Help: upload a list of SMS contacts · Klaviyo Help: indicate country for SMS import

E) One click unsubscribe

Check headers for List Unsubscribe and List Unsubscribe Post One Click. Process removals within 48 hours.
Klaviyo Help: understanding unsubscribes

F) Warming thresholds

• Scale when: bounces are under 1 percent, spam complaints under 0.1 percent, CTR stable, opens indicative 20 to 30 percent.
• Throttle back when: complaints rise or bounces increase. Reduce audience, improve content and cadence.

G) Platform specific tips

• Mailchimp to Klaviyo: use the official migration or integration and turn off Mailchimp flows afterward to avoid double sending.
• Yotpo to Klaviyo: sync profiles and subscriptions. Plan number porting early.
• Shopify, BigCommerce and Woo: verify Viewed Product and Started Checkout events before going live.

Common mistakes and how to avoid them

• Forms not migrated: new leads still go to the old ESP. Point all sources to Klaviyo and test.
• Suppressions not imported: leads to complaints and reputation damage. Upload unsub and bounce CSVs to the suppression list before your first campaign.
• Scaling too fast during warming: use Guided Warming and respect KPI gates.
• Imported contacts receiving Welcome: filter on source=import.
• One to one reporting comparisons: document attribution, standardize UTMs and compare trends and segments.

Sample timeline and project plan

1. Week 1: DNS and branded sending domain. Dedicated click tracking with SSL and CAA. IP strategy. Data map. Migrate forms.
2. Week 2: Import Email and SMS. Suppressions. Core flows live. Campaign 1 to 30 day engaged under 10,000 recipients.
3. Week 3: Guided Warming and Campaign 2. A or B tests. Post purchase and win back live.
4. Week 4: Further scale. Review and VIP flows. GA4 calibration and a 60 day roadmap.

Downloads and tools

• Migration checklist (XLSX, EN) · NL
• Data mapping template (XLSX, EN) · NL
• Warming scenarios (XLSX, EN) · NL
• Flow library (XLSX, EN) · NL

FAQ about migrating to Klaviyo

Work with us

Polaris Growth migrates and optimizes your entire Klaviyo setup for Email and SMS. We safeguard deliverability, rebuild flows and forms and roll out in phases that grow revenue without reputation risk.

• Book a free migration consult
• Klaviyo services
• Case study: Moooi Migration
• Blog: RFM and RFM Segmentation