A replenishment flow reminds a customer to reorder a product they are about to run out of. For brands selling consumables, it is one of the highest-leverage automations you can build, because the customer already likes the product and the only job is timing.
That word, timing, is where almost every replenishment flow fails. A brand picks a round number, 30 days, 45 days, 60 days, builds the whole flow off it, and then wonders why the revenue is underwhelming. The number was a guess, and the flow inherited it.
This covers how to set the timing from your actual data instead of a guess, the trigger and suppression, the email sequence, the discount maths, and when to reach for predictive timing instead of a fixed delay.
First, is replenishment even right for your store?
Replenishment is for products customers use up and rebuy on a cycle. Skincare, supplements, coffee, pet food, refills, consumable razor-blade-model products where one purchase creates a recurring need.
It is not for fashion, durable home goods, electronics, or a single hero product people buy once. If your customers do not have a natural reorder cycle, this is the wrong flow, and a post-purchase or cross-sell flow will serve you better.
If you do sell consumables, keep going. This is one of the most underused flows in DTC.
Set the timing from your data, not a round number
This is the decision that makes or breaks the flow, so do not guess it.
The goal is simple: send the reminder a few days before the customer runs out, so the reorder arrives before they go without and before they look elsewhere. Send too early and you are nagging people who still have products. Send too late and they have already run out, maybe already rebought from someone faster.
To find the right delay, pull your real reorder interval out of Klaviyo rather than inventing one. If you do not have predictive analytics, the manual method is straightforward:
- Build a segment of customers with more than one order
- Export to CSV and pull the average days between orders field
- Look at the average across your repeat buyers
That number is your buying cycle. Set the first email to fire a few days before it. If your data says people reorder every 35 days, send around day 28 to 30, not day 35. You want the email landing while they still have a little product left, with enough lead time for shipping.
If you sell products with clearly different cycles (a 30-day supplement and a 90-day one), do not average them into one flow. Build a separate flow per cycle, using a trigger filter on the product, so each reminder fires at the right time for that product.
Trigger and suppression
The only trigger that makes sense is Placed Order. The flow starts when someone buys, waits out the delay, then sends the reminder.
Two filters matter:
Exit on reorder. Add a flow filter: placed order zero times since starting this flow. When the customer reorders, they drop out of the current cycle. Their new order re-triggers the flow from the start, so the timer resets and the next reminder fires a cycle later. This is what keeps the flow running cleanly on repeat without sending a reminder to someone who just bought.
Turn Smart Sending off. Same as with cart recovery. Smart Sending skips anyone contacted in the last 16 hours, which means a customer who happened to get a campaign that day silently misses the replenishment email. The entire value of this flow is that it lands at the right moment. Do not let Smart Sending suppress the one email whose timing you worked to get right.
The email sequence
Two to three emails around the reorder point, not one. A single reminder catches the people who were ready anyway and misses everyone who needed a second nudge.
Email 1: the reminder (a few days before runout)
Straightforward and friction-free. “Running low?” with the product they bought and a one-click reorder button. No discount. Most people who are going to reorder will do it here, at full price, because they need the product. Do not discount a sale that was going to happen anyway.
Email 2: the nudge (a few days later)
For the people who did not act on the first. Same core message with a little more push: reinforce why they liked it, make reordering effortless. Still usually no discount.
Email 3: the incentive (optional, after the cycle)
If they still have not reordered, they may have drifted or bought elsewhere. This is the only place an incentive belongs, and it should be time-limited. A modest discount or free shipping to win back the reorder you were otherwise going to lose.
After this, exit the flow. Continuing to chase a reorder that is not coming just costs you unsubscribes.
Source: Graza
The discount maths most brands get wrong
The instinct is to put a reorder discount in every email. It is expensive and usually wrong.
A customer reordering a consumable they use and like does not need a discount to do it. They are going to rebuy anyway. Every percentage point you hand them on email 1 is margin given away on a sale you already had. That is why the discount belongs at the end, conditionally, for the people who did not reorder on their own.
Run the simple maths before you set any offer: the discount only makes sense if it recovers reorders you would otherwise lose. On the early emails, where most reorders happen at full price, it does not. If you want to be precise about which customers actually need an incentive, that is a conditional-split build worth adding once the core flow is working.
Fixed delay vs predictive timing
There are two ways to time this flow, and the right one depends on your products.
Fixed time delay (recommended for known cycles). If your products have a clear, consistent buying cycle, a fixed delay built from your average-days-between-orders data is the better choice. It is precise, it is predictable, and crucially it knows which product the customer bought, so the reminder can feature the right item.
Predicted next order date (for irregular cycles or new customers). Klaviyo’s predictive analytics can calculate an expected next order date per customer and trigger the flow on that date. This shines when reorder timing varies a lot between customers, or for first-time buyers where you have no cycle yet. It accounts for individual cadence rather than a single store-wide number.
The important caveat: the predicted date does not know what the customer last ordered or that product’s specific cycle. If you sell consumables with known, distinct cycles, Klaviyo’s own guidance is to stick with fixed-delay replenishment flows rather than the predictive trigger. Predictive is the better tool when the cycle is genuinely unpredictable, not a replacement for product-specific timing.
Predictive also needs the account to qualify: enough customers, enough order history, enough repeat buyers. If you are not eligible yet, the manual average-days method gets you most of the way there.
Priority order
If you are building this from scratch:
- Confirm replenishment fits, you sell consumables with a reorder cycle
- Pull your average days between orders from Klaviyo, do not guess
- Set a Placed Order trigger with a delay a few days before that interval
- Split into separate flows per product cycle if your cycles differ
- Add the exit-on-reorder filter and turn Smart Sending off
- Build two to three emails: reminder, nudge, optional incentive
- Hold the discount to the last email, conditionally
The timing decision and the discount decision carry most of the value. A plain two-email flow timed to your real reorder data will out-earn a beautifully designed one built on a guessed 30 days.
More advanced layers sit on top once this is working: product-level cycles via conditional splits, a first-purchase bounce-back for one-time buyers separate from the repeat-buyer flow, and a subscription push for products bought often enough to justify it. Those are worth building once the core timing is right. If you are not sure what your real reorder interval is or whether your products qualify for predictive, that is worth a closer look before adding complexity.
Free flow audit
If you want a second pair of eyes on your setup, or you suspect your flows are firing on a guessed interval instead of your real reorder data, book a free 30-minute audit with us. We will look at your buying-cycle data and where the flows are mistimed.
Or if you want to talk through strategy first: Book a strategy call
Jamie Watkins, Director at UndergroundEcom [LinkedIn] | [UndergroundEcom.com]
