Switching email marketing platforms can feel intimidating, especially if you’ve had your business for awhile and you’ve been building your email list for years. The thought of moving everything over and potentially losing contacts, breaking your automations, or tanking your deliverability is enough to keep a lot of store owners stuck on a platform they’ve already outgrown.
Here’s the reality: migrating to Klaviyo for your email marketing is very manageable when you do it in the right order. The key is not to rush it. A migration done properly over several weeks will serve you far better than one done in an afternoon. This guide walks you through every step so you arrive in Klaviyo with a clean list and everything in place to start generating results.
Step 1: Export Your Contacts From Your Current Email Marketing Platform
Before you do anything in Klaviyo, go to your existing email platform and export your full contact list as a CSV file. Most platforms make this straightforward. Look for an Export or Download option in your Contacts, Audience, or Subscribers section.
When you export, make sure you are pulling more than just email addresses. You want as much data as possible: first name, last name, phone number, tags, custom fields, and most importantly, subscription status. You need to know who is subscribed, who has unsubscribed, and who has bounced. That information is critical for the next step and will protect your deliverability in Klaviyo.
Save your export somewhere you can easily find it. You may need it more than once during this process.
Step 2: Clean Your List Before You Import
This step is the one most people skip, and it is the most important thing you can do for your long-term email performance in Klaviyo.
Before importing anything, go through your CSV and remove the following: anyone who has unsubscribed, anyone who has hard bounced, and anyone who has not opened or clicked an email from you in the last 12 months. That last group is your unengaged contacts, and importing them into a fresh account will immediately damage your sender reputation and reduce the reach of every email you send going forward.
It feels counterintuitive to shrink your list before a migration, but a clean list of 5,000 engaged subscribers will outperform a bloated list of 15,000 mixed contacts every single time. Klaviyo also charges based on active profile count, so you will save money by keeping your list tight.
If you are not sure who is engaged, most platforms let you filter by open activity in the last 90 or 180 days. Use that filter to create a subset of your most active contacts and prioritize those for your migration.
Step 3: Set Up and Configure Your Klaviyo Account
If you do not already have a Klaviyo account, head to klaviyo.com and sign up. During onboarding, you will connect your e-commerce platform (Shopify, WooCommerce, BigCommerce, and others are all supported) and Klaviyo will begin syncing your store data automatically.
Even if you are migrating from another email tool, take the time to connect your store properly during this step. The behavioral data Klaviyo pulls in from your store is what makes the platform so powerful. Your purchase history, browse activity, and order data will all be available to use in flows and segments from day one.
Step 4: Authenticate Your Sending Domain
Do not send a single email until this step is complete. Domain authentication tells the major inbox providers (Gmail, Yahoo, Outlook) that you are authorized to send email on behalf of your domain. Without it, your emails are far more likely to end up in spam regardless of how good your list is.
In Klaviyo, go to Account Settings and find the Email Sending Domains section. Add your domain and follow the instructions to update your DNS records. You will be adding CNAME and TXT records through your domain provider. Once those propagate, your domain is authenticated.
Also configure your From Name and From Email at this stage. These should be consistent with your domain and what your subscribers are used to seeing from you, so the transition feels seamless on their end.
Step 5: Set Up Your List Structure in Klaviyo
Before you import, decide how you want to organize your contacts. Klaviyo uses Lists (static groups you manually add people to) and Segments (dynamic groups that update automatically based on rules you define). For most stores, one main email list is all you need to start.
If your current platform uses multiple lists or tags to separate different types of subscribers (customers vs. prospects, for example), think about how you want to recreate that structure in Klaviyo. You may be able to handle it with a single list and segments rather than multiple lists, which keeps things simpler to manage.
Set up your list before importing so you have a destination ready for your contacts.
Step 6: Import Your Contacts
Now you are ready to bring your list over. In Klaviyo, go to Lists and Segments, open the list you just created, and select Manage List, then Import Contacts. Upload your cleaned CSV file and map your columns to the corresponding Klaviyo fields (email address, first name, last name, phone number, and any custom properties).
Once the import is complete, go through the suppression step immediately. Upload your unsubscribes and hard bounces as suppressed contacts so Klaviyo knows not to email them. This is not optional. Emailing someone who previously unsubscribed is a compliance issue, and emailing hard bounced addresses will hurt your deliverability.
To suppress contacts, go to the Suppressions section under your account settings and upload a separate CSV of anyone who should never receive emails from you.
Step 7: List Warming and Warming Up Your Sending Reputation
If you are moving from a platform where you were sending regularly, your new Klaviyo account has no sending history with the major inbox providers. That means you need to ease into your send volume rather than blasting your entire list on day one.
Inbox providers watch for sudden spikes in send volume from new domains and IPs, and they will throttle or filter your emails if you jump straight to full volume. Warming up means starting with a smaller, highly engaged segment of your list and gradually increasing your volume over two to three weeks.
Start by emailing your most engaged contacts (those who opened in the last 30 days) for the first week or two. Watch your open rates, click rates, and spam complaint rates closely. Then depending on performance, expand to a larger portion of your list. By the time you are emailing everyone, Klaviyo’s sending infrastructure will have established a positive reputation with inbox providers on your behalf.
Step 8: Rebuild Your Flows and Sunset Your Old Platform
With your contacts in Klaviyo and your list warming in progress, the last step is rebuilding your automations. Do not import flows or copy-paste from your old platform. It does not work this way. Use this as an opportunity to rebuild them properly using Klaviyo’s native flow builder, which is almost certainly more powerful than what you were using before.
Start with your highest-priority flows: welcome series and abandoned cart. Get those live first, then work through post-purchase, browse abandonment, and win-back sequences in the weeks that follow.
Run both platforms in parallel for a short time if needed, but as soon as your Klaviyo flows are live and your list is fully imported, cancel your old platform subscription. There is no reason to pay for two tools doing the same job.
If you want to make sure your migration goes smoothly or you would like help rebuilding your flows in Klaviyo the right way, we are happy to walk through it with you.
Continue reading: How to set up Klaviyo for your Shopify store and The 6 Klaviyo flows every e-commerce store needs.