- Give the customer the idea no less than 2 weeks after their order. Klaviyo's own default cross-sell flow goes out 14 days after an order is fulfilled.
- Keep texts as reminders and emails as branding and awareness. Use a text to remind people to read the email.
- I'd include a discount in an SMS upsell. To be clear, that's my preference. Nothing in Klaviyo's SMS compliance guidance requires one.
- A post-purchase upsell text is marketing, so it needs SMS marketing consent. A transactional opt-in for order updates doesn't cover it.
- Klaviyo's best practices: 1 to 2 texts a week, under 160 characters, one link, and nothing before 9 a.m. or after 8 p.m. in the recipient's time zone.
This is for Shopify founders who just turned on SMS and want to know whether, when and how to text a customer about a second purchase.
Should you use SMS for upsells after the first order?
Yes, if you keep the text in its lane.
SMS is a more urgent channel than email. Klaviyo's own SMS best practices say shorter messages, under 160 characters, tend to perform better, and that for a lot of information you should use email instead. So a text can't carry a product story, a how-to or a reason to love the brand. It can carry a reminder and an offer.
That's how I split the work after a first order:
- Emails: branding and awareness. How to use what they bought, why it's made the way it is, what else fits with it.
- Texts: reminders. The offer is live, the email is waiting, here's the link.
My take on whether SMS is worth adding in the first place is in should I add SMS marketing.
When should the first upsell text go out?
No less than 2 weeks after the order.
Before that, the customer is still waiting on the package or has only just started using it. Asking for a second purchase before they've had a fair shot at the first one is too early.
Klaviyo's help center lands in the same place for email. Its default product review and cross-sell flow goes out 14 days after an order is fulfilled, and it notes you might even wait until the customer has received the order. Klaviyo's built-in flow uses Fulfilled Order as the trigger, because it's closer to when the customer actually has the product.
Two setup details from the same Klaviyo page that carry over to a text:
- Add a filter so anyone who places another order after entering the flow stops getting the upsell.
- If you sell across categories, filter the trigger to a category or collection so the upsell matches what they bought.
If you're building the email side too, here's my post-purchase email flow.
How do you keep texts and emails from saying the same thing?
You time it properly.
The email goes out with the full message: the product, the reason, the offer. The text follows as a reminder to go read it. They work as a pair, not as two copies of the same announcement.
Klaviyo makes a version of this point in its SMS best practices: "No one wants to get the same information via email, SMS, and push all at the same time." Its example staggers channels across the day instead of firing everything at once.
In practice, that means checking your post-purchase email timing before you add the text, and placing the text on a different day than an email with the same offer, or as the follow-up a few hours later.
Should an SMS upsell include a discount?
Yes. I'd put a discount in an SMS upsell.
The text is short and lands right in someone's pocket. It needs a clear reason to act now, and an offer is the clearest reason there is.
You may have heard you have to include a discount in SMS automations after the first text. That's not a rule. Klaviyo's SMS compliance guidance doesn't require a discount or incentive anywhere. It's a choice, and it's the one I'd make for an upsell.
If you're working out how much to give away across email and SMS, my email discount strategy post covers how I think about it.
What rules apply to a post-purchase upsell text?
This is general information, not legal advice. Per Klaviyo's SMS compliance guidance:
- Marketing consent is required. Klaviyo says consent for transactional SMS, like order updates, doesn't subscribe someone to marketing messages. An upsell is marketing.
- Separate opt-in. SMS opt-in has to be separate from email. You can't use one checkbox for both.
- Quiet hours. Klaviyo notes the US TCPA allows sending from 8 a.m. to 9 p.m., and some states are narrower. Florida, for example, is 8 a.m. to 8 p.m. Klaviyo's general best practice is to avoid sending before 9 a.m. or after 8 p.m. in the recipient's local time.
- A way to opt out. Every marketing text needs one, like a STOP keyword.
- Say who it's from. Klaviyo says subscribers should know who the message is from, either with a brand prefix or a mention in the message.
And from Klaviyo's best practices for the text itself: keep it under 160 characters, use one link as the call to action, and keep the overall pace to 1 to 2 texts a week.
What should you text first if you've just turned on SMS?
Your highest-leverage marketing. Start with your biggest sends, the offers and announcements that already drive the most revenue in email, and see what works at that level first.
Once you know how your list responds to texts on your best sends, add the post-purchase upsell as an automation, 2 weeks or more after the order, with a discount and a link back to the email.
If you're still choosing a platform for SMS, I compare the main options in Klaviyo SMS vs Postscript vs Attentive. And for the bigger picture on second orders, see my repeat purchase email strategy.
FAQ
How soon after a purchase should I send an upsell text?
No less than 2 weeks after the order. Klaviyo's default cross-sell flow sends 14 days after an order is fulfilled.
Is SMS good for upselling?
Yes, as a reminder. Keep the text short with one link and an offer, and let email do the explaining. Klaviyo says messages under 160 characters tend to perform better.
Do I need separate consent to send an SMS upsell?
Yes. Klaviyo says transactional SMS consent, like order updates, doesn't subscribe someone to marketing texts. An upsell needs SMS marketing consent.
Do I have to include a discount in SMS automations?
No. Nothing in Klaviyo's SMS compliance guidance requires one. I'd still include a discount in an upsell text because it gives people a reason to act.
How many texts should I send customers?
Klaviyo's best practice is 1 to 2 texts a week. Count your post-purchase texts in that total.
Founder of Bardown Digital, a Chicago-based Klaviyo email and retention agency for Shopify brands. He's worked with brands doing $500K to $100M a year, with $100M+ in email-attributed revenue across them.