Abandoned cart email subject lines are the one-line headlines on the reminder emails sent to shoppers who left without paying. Each of the up to three emails needs its own line, written for that email’s job.
This guide gives nine lines to copy for a hypothetical candle store, then covers length and preview text, the FTC rule on deceptive lines, a margin check before a discount, and how to test your own.
What are abandoned cart email subject lines?
The first words a shopper reads in an automated reminder after leaving a checkout. They decide whether the email gets opened, so they matter more than most of the copy inside it.
The need is large, and abandoned cart email subject lines are the cheapest part of the flow to improve. Baymard Institute’s cart abandonment page puts the average documented abandonment rate at 70.22%, calculated from 50 studies (page updated September 22, 2025). Most of those shoppers are never emailed, so a flow with good abandoned cart subject lines is a second chance at a sale that already cost you the ad click.
Our abandoned cart recovery work caps each shopper at three messages and stops the sequence at purchase, so each subject line has to earn its place. Subject lines for abandoned cart emails are short, so every word counts.
Is it an abandoned cart or an abandoned checkout email?
On Shopify, it is an abandoned checkout email: the shopper must have given an email address and then not paid. Shopify’s help page says a checkout counts as abandoned if it stays incomplete for more than 10 minutes after the customer gave their email information.
That matters for abandoned cart subject lines. A shopper who reached checkout has shown more intent than one who only added an item, so a plain “you left something behind” is accurate. For a shopper who only browsed, such a line would be false, because they never started a checkout. Match the line to the trigger you really use, because abandoned cart email subject lines that describe the wrong event read as careless.
The email contains a link back to the shopper’s checkout, according to the same page. Use that: a line that points at the next step (“finish your order”) is clearer than one that only sells.
What makes the best abandoned cart email subject lines?
Lines that are true to the email, short enough to read in full on a phone, and specific to what the shopper left. Cleverness comes last, and a wrong promise costs more than a dull line saves.
Four habits cover most abandoned cart email subject lines:
- Name the product when you can. “Your Cedar & Smoke candle is waiting” is more useful than “Don’t miss out”.
- Keep it under 50 characters. This is our working guideline, not a platform rule. Send a test to a phone and see how much shows before the line is cut off.
- Do not repeat the preview text. The preview sits next to the subject line in the inbox, so the two should add up to one message.
- Say one thing. A question or a short statement works. A line that tries to remind, tempt and warn at once does none of them.
Preview text deserves its own attention when you write abandoned cart subject lines. Klaviyo’s preview text guide says it is displayed after the subject line, and that if you leave it blank, inboxes pull it from the start of the email, which can include alt text or your navigation bar. It suggests two uses: summarize the email, or complement the subject line.
For the subject line “Delivery and returns, answered”, good preview text would be “Delivery takes 3 to 5 working days, and returns are free” if that is your real policy. A blank preview would show the logo’s alt text instead.
Which abandoned cart subject line examples fit each email?
Match the line to the job of its email: remind in the first, answer one doubt in the second, and keep any offer for the third. The lines below are original, written for an invented candle store, and the counts include spaces.
Email 1, about 1 hour after the checkout is left (remind):
- “You left something in your cart” (31 characters): plain and true, the right default if you do not know which item mattered.
- “Your Cedar & Smoke candle is waiting” (36): names the product the shopper chose.
- “Did something go wrong at checkout?” (35): use it when payment errors are common, and only then.
Email 2, about 24 hours after (answer one doubt):
- “How long does the Cedar & Smoke candle burn?” (44): answers a question many first-time buyers have.
- “Delivery and returns, answered” (30): fits any product, as long as the email really does answer them.
- “Still thinking about the Cedar & Smoke candle?” (46): softer, for stores that do not want to push.
Email 3, about 72 hours after (last note):
- “Your cart is still waiting” (26): a calm last reminder, with no offer.
- “Only 3 Cedar & Smoke candles left” (33): use it only when the stock count is real and comes from your inventory.
- “10% off your candle until Sunday” (32): use it only if the margin allows it and the date is real.
These delays are a starting point for the store, not a rule from any platform. The same nine abandoned cart subject lines can be reworded for any product. Some stores send the first email sooner, some later. Test it, and keep the same cap of three.
Are urgency and discounts safe in abandoned cart subject lines?
Only if they are true. That goes for every one of your abandoned cart email subject lines. The FTC’s CAN-SPAM guide says not to use deceptive subject lines and that the subject line must accurately reflect the content of the message.
The same guide says each separate email in violation can carry penalties of up to $53,088. A fake “last chance” or a “Re:” that pretends to be a reply is therefore a legal risk as well as a trust problem.
Two practical tests keep urgency honest:
- Is there a real deadline in the email, such as an offer that ends on a set date?
- Would the shopper find the same offer again next week? If so, “last chance” is false.
A discount line needs one more check, which is the margin. Example: a hypothetical order of $60 with a 50% margin earns $30. Taking 15% off costs $9, so the order now earns $21. That is 30% less profit on the order you were trying to save.
If the margin on that item cannot take the cut, keep the third subject line plain, or offer something other than a price cut, such as free shipping. Do not send an offer to every cart: our own flows limit extra incentives to eligible first-time carts.
How do you test abandoned cart email subject lines?
Change one thing in one email, split the recipients evenly, and wait several weeks. A small store gets few sends, so a short test mostly measures chance.
Klaviyo supports testing abandoned cart email subject lines inside a flow. Its flow email test guide says you can test the subject line, weight each variation, and have a winner chosen automatically once statistical significance is reached. It generally recommends equal weights, and the winner is chosen on click rate by default, although you can change that.
Its campaign test guide lists three simple subject line variations that are worth copying: personalization against none, short against long, and a question against a statement. Choose one per test when you compare abandoned cart subject lines.
A worked example of why patience matters. Suppose a store sends 1,200 abandoned cart emails a month, and the flow splits them into 600 per line. If line A gets 5% clicks (30) and line B gets 6% (36), line B looks 20% better. Yet the gap is 6 clicks, and chance alone can produce that. Run the test for several months of sends, or until the platform reports a clear winner, before you change the flow. For the logic behind this, see A/B testing.
Judge the winner among your abandoned cart email subject lines on recovered orders when you have enough of them. Clicks are a quicker signal, but a curious subject line can win clicks and lose sales.
How do you change the subject line in Shopify or Klaviyo?
For abandoned cart email subject lines in Shopify, edit the email subject in the notification template; in Klaviyo, edit it in the flow email itself. Both take a few minutes and need no developer.
- Shopify: after you confirm your sender email, you can edit the Email subject and Email body (HTML) of a notification, according to Shopify’s notification template guide. The automatic abandoned checkout email has a Send after setting and a Customize email button in the abandoned checkouts settings.
- Klaviyo: open the flow email, then edit the subject line and preview text. In an A/B test you select a variation and edit its own subject line, preview text and sender name.
Shopify deletes abandoned checkouts older than 3 months from the admin, so keep your own record: store the winning line and the date you changed it. If recovered orders fall a month later, you will know which change to look at first.
Run the six checks above on every one of your abandoned cart email subject lines before it goes live. If you would like a second pair of eyes on your whole flow, our free audit covers it, and Klaviyo email marketing is the service behind it. For tool costs, see email marketing cost, and for the metric itself, cart abandonment rate. More email and store guides are in e-commerce guides.