Replenishment Email: Timing and Triggers

A replenishment email is a reorder reminder timed to when a customer is about to run out. Send the first at roughly 80 to 85 percent of the consumption cycle, a second shortly after it ends, and a third with an incentive only if those fail. The cycle comes from your own order data, not a template default.

Why the timing is the entire mechanic

A replenishment email has one job and a narrow window in which to do it. Too early and the customer has product left, so the email is noise and the reorder they eventually make gets no credit. Too late and they have already bought a substitute, which is the outcome the flow exists to prevent.

Klaviyo's own guidance puts the first send before the cycle ends rather than at it: for "a supplement that comes with a 30 day supply, you'll most likely want to send a reminder email about 25 days after customers enter the flow". Its rule of thumb is two reminders, "and then one follow-up after the projected buying cycle has passed that includes an extra incentive like a discount or a coupon".

Work out your own cycle from order history rather than from the pack size. Take the median days between consecutive orders for customers who have ordered the same product three or more times. Pack size tells you the intended cycle; order history tells you the real one, and for most consumables the real one is longer because people skip days. If those two numbers are far apart, the pack-size assumption is what has been quietly costing you reorders.

Split the cycle by product, not by brand. A customer buying a daily supplement and a monthly cleanser has two cycles, and one blended average serves neither. If your catalogue spans both, the flow needs to read the product rather than the customer.

The economics that justify the build

Replenishment is not a marginal optimisation. It sits exactly where the money is. Bluecore's 2025 Customer Growth Benchmarks Report, covering more than 100 retailers across seven verticals and analysing the full 2024 calendar year, found the average retailer retained only 6 percent of new customers after three years, and that nearly three-quarters of a retailer's customers are one-and-done. It also found that once someone buys twice, the likelihood they buy a third time rises by 95 percent.

There is a second reason to put effort here rather than into campaigns. Klaviyo, across a benchmark set of more than 183,000 customers, reports that flows generate nearly 41 percent of total email revenue from just 5.3 percent of sends. Automated, triggered mail does the disproportionate work in every ecommerce account, and for a consumables catalogue the replenishment trigger is the one closest to the money.

For a consumables brand, the reorder is the second purchase. That makes the replenishment email the highest-leverage automation in the account, because it is the one asset positioned directly on the transition that changes a customer's value.

Compare that to what the flow costs: one automation, one product-level cycle calculation, three emails. Against a retention curve where 94 percent of new customers are gone within three years on the industry average, the arithmetic is not close. It is the cheapest structural intervention available to a consumables brand, and it is the one most often left until after the campaign calendar is full.

What nobody will tell you: there is no benchmark

Here is something you will not find on the other pages ranking for this term. No major platform publishes engagement benchmarks for replenishment emails as a named automation type.

Klaviyo's flow benchmark documentation covers abandoned cart, post-purchase and welcome series. Its industry benchmarks break out campaigns against flows and then by vertical, not by individual flow. Omnisend's automation tables, which do break out flow types in detail, list order confirmation, post-purchase, cross-sell, welcome, cart abandonment and back-in-stock. Replenishment appears in none of them.

That matters practically. If you find a page quoting a replenishment email conversion rate, it is either invented or lifted from a different automation and relabelled. Do not set your targets from it, and do not let an agency set yours from it either.

What you can benchmark against is your own baseline. Measure the second-order rate for customers who entered the flow against those who did not, over one full consumption cycle. That comparison is available to you, it is specific to your catalogue, and it is worth more than a borrowed industry average would be even if one existed.

Our retention email programmes team calculates the cycle per product before writing a single email.

How to find your cycle from order data

You do not need a data team for this. Pull every customer who has ordered the same product three or more times, take the gap in days between each consecutive pair of orders, and take the median of those gaps. The median, not the mean: a handful of customers who reordered after eight months will drag a mean badly and set your first send far too late.

Do it per product, or at least per category. Then compare the result to the pack size. If the pack is a 30-day supply and the median gap is 41 days, your customers are using it more slowly than the label assumes, and a day-25 send is nine days early for most of them.

Segment the result once more if your data supports it. Customers on their first reorder behave differently from customers on their fifth: the experienced ones have a rhythm and respond to a short reminder, the first-timers often need the reason as well as the prompt. If you can only build one flow, build it for the first reorder, because that is the transition worth causing.

Recalculate quarterly. Pack sizes change, formulations change, and a cycle set at launch drifts.

Copy that works in a reorder email

Lead with the product, not the brand. The customer is not deciding whether to buy from you, they are deciding whether they need more of a thing they already chose. "Running low on the Daily Greens?" does more work than any subject line about your range.

Do not open with a discount. The customer is running low, which means the decision is already leaning your way, and a discount in the first email converts a full-price reorder into a cheaper one for no gain.

Make the reorder one action. A link that lands on a pre-filled cart with the same variant, quantity and address converts at a different level than one that lands on a category page. If your platform supports one-click reorder, that single change is usually worth more than everything else in this section combined.

Keep the body short. Three lines, a product image, a button. This is not the email in which to explain your sourcing, and a long reorder email reads as a sales pitch for something the customer already owns.

State the quantity and the price. A reorder prompt that hides the price reads as a trick, and the customer has bought this before, so there is nothing to discover.

Replenishment is not a subscription, and the difference is the offer

A replenishment email asks someone to buy again. A subscription asks them to stop deciding. They solve the same problem with different commitments, and the mistake is treating the email as a funnel into the subscription by default.

Run them as alternatives on the same trigger. The replenishment email should carry a one-click reorder as the primary action and the subscribe option as the secondary, not the reverse. Customers who have reordered manually two or three times are the right audience for a subscription pitch, because they have demonstrated the cycle. Customers on their first reorder have not, and asking them to commit is how you lose the reorder you already had. Put the subscribe option in the third email at the earliest, and only for customers who have reordered before.

Where a subscription does exist, the replenishment flow must suppress active subscribers entirely. A reorder reminder to someone whose next shipment is already scheduled is the clearest possible signal that nobody is reading their account, and the churn work that follows costs more than the email earned. That coordination sits with the subscription programme.

Suppression and the three rules that keep it clean

Suppress anyone who has reordered since entering the flow, immediately, from every remaining send. This is the rule most in-house builds get wrong, and it is the one that produces complaints.

Suppress active subscribers, as above. Suppress anyone with an open support ticket on the last order, because a reorder prompt in the middle of an unresolved problem reads as tone-deaf.

Then cap the flow against your campaign calendar rather than separately from it, so a customer in the replenishment window during a promotional week does not receive five emails. The subscriber experiences one stream and does not know which system sent what, so two independent caps are functionally no cap. If your SMS programme also runs a reorder reminder, the two need one shared cap and a minimum gap between touches, not two independent schedules.

Finally, hold the incentive back. The third email is the only one that should carry a discount, and only when the first two have not worked. Leading with a discount teaches customers to wait for it, which converts a full-price reorder cycle into a discounted one and is the most expensive mistake available in this flow.

In-body table: First send day by consumption cycle