Klaviyo Email
Verification Integration
Klaviyo is one of the most powerful email and SMS marketing platforms for ecommerce brands — but sophisticated flows and segments mean nothing if you are sending to invalid addresses. Connect to ValidEmailChecker and verify your lists directly, with no CSV exports or manual uploads.
Connect Klaviyo
Enter your Private API key
Connection Name
Klaviyo Private API Key
Where to find: Profile → Settings → API Keys → Create Private API Key (Full Access)
What You Need to Get Started
Klaviyo Account
Any plan — free or paid.
Private API Key
With List & Profiles Full Access.
Verification Credits
1 credit per email verified.
2 Minutes
Create API key + connect.
How to Connect Klaviyo
Create a Private API Key in Klaviyo with the right permissions, then connect in under a minute.
Create Your Klaviyo Private API Key
Log in to your Klaviyo account, click your profile icon in the left sidebar, and select Settings. Under Account, click API keys. Click Create Private API Key, give it a name like "Valid Email Checker Integration", and select Custom Key for the access level.
Required permissions (Full Access):
Accounts
To identify your Klaviyo account
List
To read lists and modify subscribers
Profiles
To access and update contact info
Important: Copy your API key immediately after creating it — Klaviyo only shows it once. List and Profiles both need Full Access for automatic cleaning to work. Read Access alone will not work for these scopes.
Connect Your Account
In ValidEmailChecker, go to Integrations in the sidebar (or click Bulk Upload → Connect Email Platform). Find and click Klaviyo. Enter a friendly connection name — especially helpful if you manage multiple brands — and paste the Private API Key you just copied. Click Connect Account and we will verify your key and sync your lists within a few seconds.
Quick connection test: Once connected, you should see your Klaviyo lists with subscriber counts immediately. If nothing appears, double-check that your API key has the correct permissions (Accounts, List, and Profiles at Full Access).
Select a List and Configure
You will see all your Klaviyo lists and segments with subscriber counts. Select the one you want to verify, then choose your mode: Verify Only to review results before making changes, or Clean Automatically to remove invalid and disposable emails from your Klaviyo list in real time. You control exactly what happens to each email type — unsubscribe, delete, or keep.
Tip:Start with "Verify Only" on your first run. Segments are dynamic — new subscribers matching the criteria get added automatically and will not be verified yet. Consider periodic re-verification for active segments.
Track Results in Real Time
Click Import Listand you will be redirected to the Uploads & Results page where you can watch progress in real time. No need to refresh — the page updates automatically. For large lists, feel free to close the browser; verification continues in the background. When complete, click View Results to see the full breakdown and download your verified data. If you chose automatic cleaning, changes are already applied to your Klaviyo profiles.
Want a visual walkthrough with screenshots?
Our help center has the full step-by-step guide with images for every screen.
Two Ways to Verify
Verify Only
Import and verify your list without modifying anything in Klaviyo. Review results, download reports, and decide what to do next — on your terms.
Best for:
Clean Automatically Recommended
Verify and clean in one step. Invalid emails are unsubscribed or deleted directly from your Klaviyo list — no manual work required.
You control each email type:
Tracking Your Verification Progress
Once verification starts, you are automatically redirected to the Uploads & Results page where everything updates in real time — no refreshing needed.
What you will see for each task:
Task ID
Unique identifier for this verification
List Name
Your Klaviyo list name with integration icon
Upload Date
When verification started
Total Emails
Number of profiles being verified
Status
Processing, Completed, Failed, or Deleted
Progress
Real-time percentage with progress bar
Processing
Verification in progress
Completed
Click "View Results" to see breakdown
With Warning
Some emails could not be processed (credits refunded)
Failed
Something went wrong (rare)
Managing Your Klaviyo Connection
Connection Actions
Click the three-dot menu next to any connection on your Integrations page:
Sync Now
Refresh lists to get the latest subscribers, new lists, or updated segment counts.
Rename
Change the connection display name — helpful when managing multiple brands.
Delete
Remove this connection. Does not affect your Klaviyo account, lists, or profiles.
Multiple Accounts
Managing multiple brands or client accounts? Connect as many Klaviyo accounts as you need.
Go to Bulk Upload → Connect Email Platform → Klaviyo
You will see your existing connections listed
Click "+ Add Another Account"
Enter a unique name (e.g., "Brand B — Klaviyo")
Paste the Private API Key from your other Klaviyo account
Each Klaviyo account needs its own unique Private API Key — you cannot use the same key for multiple accounts.
Credits & Billing
1 Credit = 1 Email
Same rate as all other verification methods.
Unknown = Refunded
Credits returned instantly for unverifiable emails.
Duplicates = Free
Removed before charging — you only pay for unique emails.
Balance Visible
Check credits in the top-right corner of your dashboard.
Credits Running Low?
If you do not have enough credits for your list size, you can purchase more credits instantly or set up auto-refill so you never run out during a critical verification.
Team Member Access
Team members can connect their own Klaviyo accounts and run verifications using the shared team credit balance. The account owner can see credits used by each team member in the transaction history.
Klaviyo Tips
API Key Permissions Explained
Klaviyo uses custom permission scopes for Private API Keys. Here is what ValidEmailChecker needs and why.
Read Access alone will not work for List and Profiles — you need Full Access for automatic cleaning to function.
Flows & Automations
Your Klaviyo flows are safe. Here is how verification interacts with your automations and workflows.
For Ecommerce Brands
Klaviyo is built for ecommerce — here is how to get the most out of list verification for your store.
Segments vs Lists
Both segments and lists appear in the selection screen, but they behave differently when it comes to verification.
Troubleshooting
"Invalid API Key" Error
Double-check that you copied the complete Private API key with no extra spaces. Make sure the key has not been deleted in Klaviyo. Verify that Accounts, List, and Profiles all have Full Access. Go to Klaviyo → Settings → API Keys, create a new key if needed, and paste it carefully.
No Lists Appearing
Verify your API key has Full Access for the List scope — Read Access is not sufficient. Check that you have at least one list in Klaviyo with subscribers. Click Sync Now to refresh. If lists still do not appear, try disconnecting and reconnecting with a fresh API key.
Cannot Connect Multiple Accounts
Each Klaviyo account needs its own unique Private API Key — you cannot reuse the same key across accounts. Also make sure each connection has a different name. Use descriptive names like "Brand A" and "Brand B" to keep them organized.
Verification Taking Too Long
Large lists naturally take longer. Lists under 1,000 take seconds; 10,000 emails take 5–10 minutes; 100,000+ emails may take 15–30 minutes. The progress bar updates in real time — no need to refresh. For very large lists, you can close the browser and check back later.
Changes Not Reflecting in Klaviyo
If you chose "Verify Only," changes do not sync back — that is the expected behavior. If you chose "Clean List Automatically," refresh your Klaviyo page or wait a few minutes for the interface to update. Check the profile status directly in Klaviyo to confirm changes.
Best Practices for Klaviyo List Hygiene
Before Your First Verification
Ongoing List Hygiene
Recommended Actions
Frequently Asked Questions
For active ecommerce stores, we recommend verifying your main newsletter list monthly, before every major campaign (Black Friday, product launches, seasonal sales), and quarterly for less active segments. Email data decays at roughly 2% per month, so regular verification prevents deliverability issues.
Yes! Segments appear alongside lists in the selection screen. Just remember that segments are dynamic — new subscribers matching your segment criteria will be added automatically after verification, and those new contacts will not be verified yet. For dynamic segments, consider periodic re-verification.
No. Verification does not change your flow logic, triggers, or automations. It only affects individual profile statuses (subscribed → unsubscribed) if you choose "Clean List Automatically." Your welcome series, abandoned cart flows, and other automations continue running as normal.
Yes, but we recommend verifying by list or segment for better control. If you have one master list with everyone, you can verify that. For very large databases, verifying in batches gives you more granular control over cleaning actions.
Absolutely. We only read your lists and profiles to verify emails. Your API key is encrypted and stored securely. We do not store your contact data permanently — everything is deleted after 15 days. We never send emails, access your campaigns, or modify your flows.
Yes. Each Klaviyo account needs its own unique Private API Key — you cannot use the same key for multiple accounts. Give each connection a descriptive name (like "Brand A — Klaviyo" vs "Brand B — Klaviyo") so you can tell them apart.
If we cannot determine whether an email is valid or invalid — for example, if the mail server did not respond or timed out — the result is marked as "Unknown" and the credit is automatically returned to your account. You only pay for definitive results.
No. The integration works with any Klaviyo plan, including the free tier. As long as you can create a Private API Key with the required permissions, you are good to go.
Ready to Clean Your Klaviyo Lists?
Sign up, connect your Klaviyo account, and verify your first list in under two minutes. 200 free credits included — no credit card required.
Get Started Free200 free credits · No credit card · Results in minutes