You clean up a Klaviyo list by building a sunset flow that gives lapsed subscribers one last set of messages, suppressing anyone who does not respond, and then sending your campaigns to an engaged segment rather than your full list. Suppressed profiles keep their purchase history but stop counting towards your bill, so a proper cleanup makes your account cheaper and your deliverability better at the same time. It is the highest-return hour you can spend in Klaviyo, and most brands have never done it.
An active profile in Klaviyo is any contact who could receive a marketing message from you. That means anyone who has not unsubscribed, been suppressed, or been deleted. It does not mean anyone you have actually emailed.
That distinction is the whole story. Until February 2025, Klaviyo billed on emailed profiles, so contacts you quietly ignored cost you nothing. Since the change, every dormant sign-up from three years ago, every guest checkout that never opted in, and every row of that spreadsheet somebody imported in a hurry is on the meter. Plenty of brands watched their bill climb without adding a single new subscriber, and never worked out why.
Before you can clean anything, it helps to be clear on the two things Klaviyo groups people with, because mixing them up is what creates the mess in the first place.
Defined by conditions rather than membership. People move in and out automatically as their behaviour changes, so a segment always reflects reality right now. This is what you should be sending campaigns to.
A fixed collection of people who subscribed. Lists only grow as new people join, and they do not respond to behaviour. Klaviyo recommends one main list per channel, holding everyone who has consented.
Your Klaviyo bill tracks the size of your database, not your send volume or your revenue. Holding ten thousand people who will never buy again costs exactly the same as holding ten thousand loyal customers. This is the cost most brands accept without ever questioning it, because the bill arrives quietly and rises gradually.
Deliverability is judged on how people respond to your mail. Gmail asks bulk senders, meaning anyone sending 5,000 or more messages a day to Gmail accounts, to keep spam complaints under 0.1%, and starts blocking around 0.3%. Complaints come overwhelmingly from people who forgot they signed up. Keep mailing them and you damage placement for your best customers too, because reputation is measured at the domain level, not per recipient.
A 22% open rate across a bloated list tells you nothing useful. It might be a genuinely engaged audience performing poorly, or a strong audience being dragged down by thousands of dead addresses. Until the list reflects real people, every test you run and every decision you make is based on a diluted number.
This is a single afternoon of work, and then it runs itself. Do it in this order.
Start with the number, because it is usually worse than people expect. Check your active profile count against your plan limit, then compare it to how many people actually opened anything in the last 90 days. The gap between those two figures is your cleanup opportunity.
Settings → Billing → Account Usage
While you are there, note whether Klaviyo has auto-upgraded your tier at some point. It sends an email when you cross a threshold. It does not send one when you drop back below it.
Before you remove anyone, define who you actually want to keep talking to. This becomes your default campaign audience from now on, and it is the single change that most improves deliverability.
A sensible starting definition is anyone who has opened or clicked an email in the last 90 days, or placed an order in the last 180 days. Tighten to 60 days if your reputation is already struggling, and loosen to 120 if you sell something people buy rarely.
Audience → Lists & segments → Create list / segment
Now define the opposite: people who have gone genuinely quiet. Klaviyo ships a prebuilt Sunset segment in the segment library, so you can start there rather than from a blank screen.
A solid definition combines three conditions rather than relying on engagement alone: has not opened or clicked in 90 days, has been on the list at least 120 days, and has not placed an order in 180 days. That last condition matters more than people realise, because a customer who buys every six months without ever opening an email is not disengaged, they just do not read your emails. Adjust the purchase window to your product: shorter for consumables, considerably longer for durables.
A sunset flow is a segment-triggered automation, so people enter it the moment they meet your sunset conditions. That means you build it once and it keeps working, rather than becoming an annual project you dread.
Flows → Browse flow library → Sunset unengaged subscribers
Two or three messages is plenty. Acknowledge the silence honestly, make the offer genuinely worth opening, and be clear that this is the last one unless they act. Expect to recover a useful minority, which is real revenue you would otherwise have thrown away. Add a flow filter so anyone who does engage exits before the suppression step.
The end of the flow suppresses whoever did not respond. Suppression is the right action for almost every ecommerce brand, because the profile stays in your database with its order history and predictive metrics intact, it just stops receiving marketing and stops counting towards your bill.
Then do the step everybody forgets. Klaviyo will not lower your plan tier for you. Go back into billing and move it down manually, or you will keep paying the higher rate on a list you have already cleaned.
One caution before you undo anything: once a profile has been unsuppressed there is roughly a 90 day wait before it can be suppressed again. Bulk un-suppressing to squeeze one more send out of an old list is a decision you are stuck with for a quarter.
Three different things happen to a profile that stops receiving your marketing, and they are not interchangeable.
| Outcome | Suppress | Unsubscribe | Delete |
|---|---|---|---|
| Removed from your billable profile count | ✓ | ✓ | ✓ |
| Keeps purchase history and predictive metrics | ✓ | ✓ | ✗ |
| Revenue attribution reporting stays intact | ✓ | ✓ | ✗ |
| Initiated by you rather than the customer | ✓ | ✗ | ✓ |
| Reversible | 90 day lock | If they resubscribe | ✗ |
| Right choice for lapsed subscribers | ✓ | Their call | ✗ |
| Right choice for junk data and never-buyers | Usually fine | ✗ | ✓ |
In short: suppress by default, delete only where there is no order history worth keeping, and treat unsubscribes as something the customer decides rather than something you manage.
A quick read on where you stand. Two or more on the right and there is money sitting in the fix.
We've had a great experience with Greg and Hayley at warbble·digital, who have been endlessly helpful and patient with all our team, thank you!
- Parker, H. · Jul 2025 · Customer Success Training
Let's meet for 15 minutes to look at your list health, your sunset setup, and what your account should actually cost. After the call, we'll send you a free digital strategy valued at €997.