Email Automations

Replenishment Emails: How to Time Them Around Real Customer Behavior

A replenishment email works because of timing, not because the copy is unusually persuasive.

If somebody buys a product that normally runs out after roughly 30 days, the useful email is not:

Buy again!

five days after purchase.

It is:

You might be running low.

around the point they are actually likely to need more.

That is the central idea:

Replenishment should follow consumption and repurchase behavior.

Not an arbitrary timer copied from another brand.

By Emiel Dingemans, Founder of Magicianly

What Is a Replenishment Email?

A replenishment email is an automated message sent around the time a customer is expected to need another unit of a consumable or repeat-purchase product.

Common categories include:

supplements
skincare
coffee
food
pet food
household consumables
personal care
cleaning products

It is less useful for products people rarely need to replace.

The Timing Is the Strategy

Imagine a product lasts approximately 30 days and the customer orders day 1.

A useful first reminder might arrive around day 25 to 28 depending on:

shipping time
actual usage
reorder behavior
product quantity

That gives the customer time to reorder before running out.

But do not copy day 25 into every flow.

Use your own customer and product data.

Start With Product Consumption

Ask: How long should one purchase realistically last?

Example: 60 capsules, recommended use 2 per day, theoretical consumption 30 days.

That gives you a starting hypothesis.

Then compare it with actual purchasing behavior.

Then Look at Actual Repurchase Data

Customers do not always consume products exactly as designed.

Maybe:

they forget days
multiple household members use it
they buy multiple units
usage varies
shipping takes longer
the product is used seasonally

So compare the theoretical consumption window with the real time between purchases.

The actual data should win.

Average Time Between Orders Is Better Than a Generic Timer

One of our core lifecycle principles is: build timing around actual customer behavior.

If your customers normally reorder around day 38, a day-30 reminder may be early.

If they reorder around day 24, day 30 is late.

Generic templates cannot know this.

The underlying behavior is covered in ecommerce repeat purchase rate.

Product-Level Timing Matters

If the store sells:

Product A: 30-day supply.
Product B: 60-day supply.
Product C: 90-day supply.

one universal replenishment flow does not make sense.

Use:

trigger filters
conditional splits
separate flows

depending on how the Klaviyo account is structured.

Klaviyo Replenishment Flow Setup

Klaviyo currently supports replenishment flows for products customers purchase repeatedly.

The normal technical pattern is:

trigger from Placed Order
optionally filter to product
delay according to expected replenishment timing
send reminder
exclude people who already repurchased

Klaviyo's pre-built replenishment flow also uses filters to prevent emails from continuing after another purchase occurs.

Source: Klaviyo replenishment flow documentation.

Example Flow

Hypothetical 30-day product:

Day 25: Email 1: running-low reminder.
Day 29: Email 2: convenience and reorder reminder.
Later: Potential third message only if the category supports it, the customer has not purchased and frequency does not collide with other lifecycle messages.

This is an example. Do not publish it as a universal ideal sequence.

Email Example 1: Simple Reminder

Subject: Running low?

If you're using NOVA daily, you may be getting close to the bottom of your current supply. You can reorder here: [Reorder]

That is enough. The timing does most of the persuasion.

Example 2: Convenience

Subject: Need another one?

Your last NOVA order was a few weeks ago. If you're running low, reorder before you run out: [Reorder]

No discount required.

Example 3: Education Plus Reorder

Subject: One thing before you restock

A quick reminder on how we recommend using NOVA consistently: [Usage tip]. If you're nearly out, your next order is here: [Reorder]

Useful when correct product use matters.

Example 4: Product-Specific Replenishment

Subject: Time to restock your Daily Cleanser?

If you're using it morning and evening, your current bottle may be getting low. [Restock Daily Cleanser]

This is more useful than:

Shop our store.

Example 5: Plain-Text Reminder

Subject: running low?

Hey, quick one. If you've been using NOVA regularly, you're probably getting close to the end of your first order. Here's the quick reorder link if you need it: [link]. Emiel

Illustrative example only.

Do Not Lead With a Discount

If somebody already needs another unit, the customer has a natural reason to purchase.

Do not automatically teach them:

Replenishment time = coupon time.

Start with:

timing
utility
convenience

Then test incentives where strategically necessary.

Exclude Active Subscribers

This is important.

An active subscriber already has another order scheduled.

They generally do not need:

You might be running low, buy another.

Instead, they need the subscription-specific upcoming-order experience.

That side of the lifecycle is covered in ecommerce subscription marketing.

Coordinate Replenishment With Post-Purchase

The customer does not know:

This email is from Flow A.

They only know:

This brand emailed me.

Map:

post-purchase
replenishment
winback
campaigns
SMS

side by side.

Do not let post-purchase email Monday, replenishment Wednesday, winback Friday and campaigns in between create accidental overmailing.

The sequencing rules are in the ecommerce post-purchase flow.

Replenishment Should Come Before Winback

Conceptually:

Post-purchase: Support the new customer.
Replenishment: Reach them around the normal repurchase need.
Winback: Trigger after they move beyond expected repurchase behavior without buying.

If average repurchase happens around day 35, waiting until day 90 to begin retention intervention may be far too late.

This is one of the practical decisions inside customer retention marketing.

Replenishment vs Subscription

For a strong recurring-consumption product, replenishment can also reveal subscription opportunity.

If a customer repeatedly buys, the value proposition becomes simple:

Instead of remembering to reorder every month, have it arrive automatically.

That is a natural time to introduce subscription.

Not necessarily in the first post-purchase email.

Klaviyo Expected Date of Next Order

Klaviyo also provides predictive analytics for eligible accounts, including Expected Date of Next Order.

Klaviyo says this prediction uses:

the specific customer's order behavior
order behavior across the account

This can provide useful customer-level context.

Source: Klaviyo predictive analytics documentation.

However, Klaviyo also notes that Expected Date of Next Order is not based on product-level purchase sequencing in the same way some of its product analytics are.

So for a product-specific replenishment flow, actual product consumption and product-level repurchase behavior can still be more useful than relying blindly on one account-wide predictive date.

Customers With Multiple Units

If somebody buys 3 units of a 30-day product, do not send the same day-25 replenishment reminder as someone who bought one.

Where order data permits, adjust based on:

quantity
pack size
variant
product
subscription status

This is where more sophisticated logic can create a better customer experience.

What About SMS?

SMS can work for replenishment where:

consent exists
timing is strong
the product is genuinely likely to be running out
the customer has not repurchased
the channel is not being overused

Klaviyo supports SMS in replenishment flows where SMS is enabled.

Source: Klaviyo SMS in flows documentation.

But do not automatically add an SMS because the flow builder allows it. The interruption must still be useful.

Metrics to Track

Reorder conversion: Did people reorder after entering the replenishment period?
Time to next purchase: Did the flow move purchases closer to the expected need?
Revenue per recipient: Useful for comparing versions.
Discount usage: Are you unnecessarily subsidizing natural repeat behavior?
First-to-second purchase rate: For first-time customers, does replenishment improve the second-order transition?
Unsubscribe: Is the timing or frequency irritating customers?

What to Test

Useful tests:

timing
one reminder vs two
plain text vs designed
product education vs simple reminder
subscription CTA
incentive vs no incentive
send timing by product
customer segments
email vs email plus SMS

Replenishment Mistakes

Generic 30-day timer: Different products behave differently.
Ignoring quantity: Three units last longer than one.
Sending to active subscribers: Their reorder is already automated.
Automatic discount: You may be paying customers to do what they were about to do anyway.
No purchase exit filter: The customer repurchases and keeps receiving reorder reminders. Bad experience.
Overlapping with winback: Two flows solve different stages. Map them together.

Our Replenishment Framework

Identify repeat-purchase products.
Calculate intended consumption.
Analyze real repurchase timing.
Segment by product and quantity where useful.
Send before the customer runs out.
Remove recent repurchasers.
Exclude active subscribers.
Coordinate with post-purchase and winback.
Test timing before endlessly rewriting copy.

The biggest lever is usually when the message arrives.

Our Verdict

A replenishment email should feel less like marketing and more like useful timing.

The best version reaches the customer when they are already starting to think:

I need another one soon.

At that point, you do not need to manufacture demand.

You simply make the next purchase easier.

Frequently Asked Questions

What is a replenishment email?

A replenishment email is an automated reminder sent around the time a repeat-purchase product is expected to run low.

When should replenishment emails be sent?

Base timing on product consumption and actual customer repurchase data. Do not use one universal timing rule across every product.

Should replenishment emails offer a discount?

Not automatically. If the customer naturally needs another unit, timing and convenience may be enough.

Can Klaviyo create replenishment flows?

Yes. Klaviyo supports replenishment flows triggered from purchase events with time delays and filters to remove customers who already repurchased.

Should subscribers receive replenishment emails?

Usually not for a product already covered by their active subscription because the next order is already scheduled.

How many replenishment emails should I send?

There is no universal number. Start with the minimum number needed to be useful and test based on repurchase behavior and customer response.