Replenishment email timing: how to pick the reorder window for each product

Why does replenishment email timing matter so much?

Because the reorder reminder is one of the highest-earning emails a consumable brand can send, and timing decides whether it works. Across four consumable brands in my data, replenishment flows earned about $2.23 per person. A skincare brand's reorder reminder flow grew 496% in one month as new customers hit their reorder window.

That second number is about timing. The flow paid off when customers reached the point where they were running low.

Get it wrong in either direction and you lose. Too early and they still have half a bottle, so they ignore it. Too late and they've already bought from someone else, or gotten used to living without it.

If you don't have a reorder flow yet, start with the setup in my Klaviyo replenishment flow post. This one is about getting the timing right.

How do you pick the reorder window for a product?

Start with three inputs for each product.

1. Supply length. How long one unit lasts at normal use. A 30-serving tub taken once a day is a 30-day supply. Skincare and snacks are fuzzier, so use your best honest guess.
2. Quantity bought. Two units last twice as long. Your timing has to account for this, or multi-pack buyers get nagged early.
3. Actual time between orders. How long customers really wait before buying that product again. People skip days, share with a partner, or stretch the last bit. Pull this from your order data for customers who've bought the product more than once.

Then set the first reminder a few days before the expected run-out date. That gives them time to order and get it shipped before they're empty. Klaviyo's own example is a 30-day supply with a reminder around day 25.

After that, Klaviyo's rule of thumb is two reminders, then one follow-up after the expected buying cycle has passed. I'd use that as the default shape and adjust once you see where the orders land.

Here's a made-up example to show the math. Say you sell three products:

The numbers are illustrative. Yours come from your products and your order history.

What about multi-packs and bundles?

This is one of the most common questions in the Klaviyo community. One founder selling a 90-day supplement asked how to keep customers who bought two or more units out of the reminder. Another wanted reminders at 20, 40, 60 and 80 days depending on how many units were in the order.

The answers come down to two options:

• Exclude multi-buyers. Add a filter so only single-unit orders enter the flow. Simple, but those customers get no reminder at all.
• Split by quantity. Keep one flow and send each quantity down its own path with its own delay. Klaviyo staff in that thread recommended triggering on Placed Order and using trigger splits on item count. They noted Klaviyo records a separate Ordered Product event for each item inside the order.

I'd lean toward splitting. A customer who bought a three-pack is often your best customer, and they need a reminder too, just later.

Bundles work the same way. Treat each bundle like its own product with its own supply length, then time the reminder off that.

Whichever you choose, preview who actually enters the flow before you turn it on. Quantity data doesn't always sync the way you expect.

How do you exclude active subscribers?

Active subscribers already have their next order on the way. A "running low?" email just confuses them, and at worst nudges them to place a duplicate order or cancel.

Another real community question came from a brand whose customers were on 4, 5 and 6 week subscriptions. The suggested fix was to sync subscription data into Klaviyo through an app like Recharge, then add a flow filter that keeps subscribers out. Recharge sends events like "Subscription started on ReCharge" and "Subscription cancelled on ReCharge" into Klaviyo, which you can filter on.

Here's how I'd think about it. Anyone with an active subscription skips the replenishment flow. They get a pre-charge reminder instead, which is its own flow. I cover that in the post on subscription churn emails.

The exact filter depends on your subscription app and how its data lands in Klaviyo. Check it with a test profile before going live.

Which products shouldn't get a replenishment email?

Anything that doesn't run out. Devices, tools, accessories, gift sets and one-time kits shouldn't trigger a reorder reminder.

The fix is in the trigger. Only let orders containing a consumable product into the flow, and filter by that product. If someone buys a device and refills together, time the reminder to the refill.

Should you use Klaviyo's expected date of next order?

Klaviyo's predictive analytics include an expected date of next order for each customer. It only shows up once at least 500 customers have ordered, you have 180 days of order history with orders in the last 30 days, and some customers have 3 or more orders.

In another community thread, a founder with a consumable product asked whether to use that prediction or fixed delays. Klaviyo's answer: for products with a known supply, fixed product-based timing makes sense. The prediction is most useful for new customers and products with irregular use. Klaviyo also warns against counting down to the expected date for repeat customers, because they'd get the same emails before every order.

So for most consumables, I'd time it off the product and use the prediction as a cross-check.

How do you know if your timing is right?

Look at where the reorders happen, not just whether they happen.

• Lots of reorders before email 1 sends? You're probably late. Pull the first reminder earlier.
• Email 1 gets clicks but email 2 or the follow-up gets the orders? You might be a little early, or the first email isn't giving people a reason to act.
• Almost nothing at any step? Check the basics before the timing. Make sure the trigger fires, the filter isn't blocking everyone, and every link works.

Judge each email by clicks and orders, not opens. If you have the volume, A/B test the delay on the first reminder and let the orders pick the winner.

Where these numbers come from

The $2.23 per person figure comes from pooled data across 4 consumable brands: 2,897 campaigns and $17.7M in email revenue. It's a small sample, so treat it as directional. The 496% figure is from a single skincare brand in one month.

FAQ

WRITTEN BY Jack White

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.

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