Birthday Email Marketing: Birthday + Anniversary Flows
How ecommerce brands run birthday and anniversary email flows: collecting birthdays, what to offer, timing, and the exact Klaviyo setup with unique codes.
Table of contents
- Why birthday and anniversary flows are worth building
- How to collect birthdays
- What to offer in a birthday email
- Birthday email timing
- Subject line ideas
- How to build a birthday flow in Klaviyo
- Anniversary emails: the flow for brands without birthday data
- Types of anniversary email
- How to build a first-order anniversary flow in Klaviyo
- What to include in an anniversary email
- Metrics to track
- Common mistakes
- Build the personal layer
- Sources
Birthday emails are one of the few automated emails a customer actually looks forward to. They are personal, they are expected, and they come with a gift. Yet most ecommerce brands either never collect birthdays or collect them and never build the flow.
This guide is about birthday and anniversary emails as a marketing programme for ecommerce brands: how to collect the data, what to offer, when to send, and how to build both flows in Klaviyo. (If you were looking for free birthday e-cards, this is not that page.)
Why birthday and anniversary flows are worth building
- They are personal by design. The trigger is the customer’s own date, so relevance is built in.
- They are annual and automatic. Build once, and the flow runs every year for every customer with a date on file.
- They give a reason to email that is not a sale. Useful in a calendar dominated by promotions.
- They support loyalty. Birthday rewards and anniversary milestones fit naturally into a loyalty programme.
- They create first-party data value. Asking for a birthday, and delivering something good on the day, shows customers why sharing data with you is worth it.
How to collect birthdays
You cannot send a birthday email without a birthday. Collection points, roughly in order of volume:
- Sign-up forms. Add an optional birthday field to your pop-up or embedded form, or as a second step after the email is captured so it does not hurt conversion. See our pop-up best practices.
- Welcome series. One email in your welcome flow: “Tell us your birthday and we’ll send you something.” Link to a short form.
- Post-purchase. A “complete your profile” ask a week or two after the first order.
- Account and preference centre. A birthday field on the account page.
- Loyalty programme. Many loyalty apps collect birthdays for birthday rewards and can sync them to your email platform.
- Quizzes. If you run a product-finder quiz, a birthday question fits naturally at the end.
Practical rules:
- Ask for month and day only unless you genuinely need the year. You rarely do, and customers are more willing to share less. Collect only the data you need.
- Say why you are asking. “So we can send you a birthday gift” converts better than an unexplained field.
- Use a consistent date format. Klaviyo needs the date in one of its accepted date formats (for example YYYY-MM-DD or MM/DD/YYYY) for it to trigger a flow.
- Age-restricted categories (alcohol, some supplements) may already need date of birth for age verification; keep that separate from marketing use and follow your own compliance advice.
What to offer in a birthday email
| Offer type | Best for | Watch-out |
|---|---|---|
| Percentage off (10–20%) | Broad catalogues, frequent buyers | Margin; can clash with sales |
| Fixed amount ($10 off $50) | Protects margin on low-AOV orders | Needs a minimum spend |
| Free gift with purchase | Brands with a good sample or accessory | Inventory planning |
| Free shipping | Stores where shipping is a known barrier | Weak if you already ship free |
| Double or bonus loyalty points | Brands with an active loyalty programme | Only valuable if points mean something |
| Early access or exclusive product | Premium brands, launches | Needs something genuinely exclusive |
| No offer, just a greeting | Luxury or high-margin brands | Lower revenue, but builds affinity |
Use unique codes. Klaviyo generates unique, single-use coupon codes for flow emails automatically on Shopify, and for flows you can set codes to expire a number of days after they are sent, so every customer gets the same window. Klaviyo adds 24 hours to the expiry you set as a buffer. A two to four week window is a sensible default.
Birthday email timing
| Send | Purpose | |
|---|---|---|
| 5–7 days before | ”Your birthday gift is here” | Delivers the offer with time to use it |
| On the day | ”Happy birthday, {{ first name }}“ | A short, warm greeting; restate the gift |
| 3–4 days before expiry | ”Your gift expires soon” | Reminder, only to people who have not used it |
If you only send a greeting with no offer, one email on the day is enough.
Timezone matters. Klaviyo recommends sending birthday flow messages earlier in the day and using the recipient’s local timezone, so a customer in Perth is not wished happy birthday a day late.
Subject line ideas
- A birthday gift for you, {{ first name }}
- It’s your birthday week, so here’s something from us
- Happy birthday from all of us at {{ brand }}
- Your birthday gift expires Sunday
How to build a birthday flow in Klaviyo
Based on Klaviyo’s own setup guide (as of September 2026):
- Go to Flows and create a flow from scratch or from Klaviyo’s library.
- Choose a date property trigger and select the property where you store birthdays. At least one profile must have the property for it to appear in the dropdown.
- Choose timing: on the birthday, or a set number of days before it. If you start before the date, Klaviyo automatically adds a target date delay (“Wait until person’s [date property]”) as the anchor for the rest of the flow.
- Set the time of day early, using the recipient’s local timezone.
- Set the flow to repeat yearly.
- Add the emails from the timing table, with a unique coupon block in the offer email.
- Add a conditional split before the expiry reminder: if the customer has placed an order since starting the flow, skip the reminder.
- Personalise with conditional splits, for example by customer status (never purchased vs customer vs VIP) or by favourite category. A VIP might get a bigger gift; a subscriber who has never bought might get a first-order incentive.
- Add SMS for subscribers with SMS consent: a short birthday text on the day works well.
Anniversary emails: the flow for brands without birthday data
If birthday collection is patchy, anniversary emails give you a personal, annual touchpoint using data you already have.
Types of anniversary email
- First-order anniversary: “One year ago today, you placed your first order.”
- Subscription anniversary: a year of continuous subscription, ideal for supplements, coffee and other replenishment brands.
- Signup anniversary: a year since joining the list.
- Loyalty tier milestones: reaching a new tier or a spend threshold.
How to build a first-order anniversary flow in Klaviyo
- Metric-triggered flow on Placed Order.
- Immediate conditional split: “Placed Order equals 1 over all time”. Splits are evaluated when the profile reaches them, so this separates first orders at the moment they happen.
- Yes branch: wait 365 days, then send the anniversary email.
- No branch: end.
- Content: thank them, recap their relationship (products bought, years as a customer), and include a loyalty reward or small gift.
If you store a first-order date as a profile property, a date property-triggered flow set to repeat yearly does the same job and can send every year, not just the first.
For subscription anniversaries, use the subscription start date or subscription events from your subscription app if they sync to Klaviyo.
What to include in an anniversary email
- A specific milestone (“12 months with us”, “your 6th order”).
- A personal recap, from order data.
- A thank-you gift or loyalty bonus.
- A soft next step: a new product in their favourite category, or a referral ask. For recommendation logic, see our cross-sell and upsell guide.
Metrics to track
- Birthday coverage: share of active profiles with a birthday on file. Aim to grow it every quarter.
- Redemption rate of birthday and anniversary codes.
- Revenue per recipient for the flow, compared with your campaign average.
- Incremental revenue: hold out a small group for a few months to see what the offer is actually adding.
Common mistakes
- Collecting birthdays and never building the flow.
- Sending at midnight UTC so half your list gets it on the wrong day.
- One generic code for everyone, shared on coupon sites within hours.
- Birthday offers weaker than your regular promotions. If the birthday gift is 10% and your weekly sale is 20%, the gift feels like an afterthought.
- No expiry, so the offer is never used.
Build the personal layer
Birthday and anniversary flows are small builds with a long tail: a few hours of setup, then a personal touchpoint for every customer, every year. They sit alongside the other drip campaigns that make up a complete lifecycle programme.
If you want birthday collection, date-triggered flows and loyalty tie-ins set up properly, our flow automation team can build them, or start with a free Klaviyo audit to see which flows your account is missing.
Sources
/ Frequently Asked Questions
Q.01 What is a birthday email in marketing? +
/ Answer
A birthday email is an automated message a brand sends to a customer around their birthday, usually with a gift: a discount, free product, free shipping or bonus loyalty points. It is triggered by a birthday date stored on the customer's profile and repeats every year. Because it is personal and expected, it tends to earn more attention than a standard promotional email.
Q.02 How can I create an automatic birthday email? +
/ Answer
Collect birthdays in your sign-up form, checkout or account page, store them as a date on the customer profile, then build a date-triggered flow. In Klaviyo, create a date property-triggered flow, select your birthday property, choose to send on or before the date, set the time in the recipient's local timezone and set the flow to repeat yearly.
Q.03 What should a birthday email include? +
/ Answer
A warm, short greeting using the customer's name, a clear gift with the terms and expiry date stated plainly, a button that applies the offer or opens the relevant products, and a sense that it was meant for them rather than blasted to everyone. Personalise product suggestions from past purchases where you can, and keep the design celebratory but on-brand.
Q.04 When should you send a birthday email? +
/ Answer
For an offer, send the first email three to seven days before the birthday so the customer has time to use it, a short 'happy birthday' on the day, and a reminder a few days before the offer expires. If you are only sending a greeting with no offer, send on the day itself, early in the morning in the customer's own timezone.
Q.05 What is a customer anniversary email? +
/ Answer
A customer anniversary email marks a milestone in the relationship with your brand, most often one year since the first order, but also subscription anniversaries or years since signing up. It thanks the customer, often recaps what they have bought or how long they have been with you, and usually includes a loyalty reward. It works well for brands without birthday data.
Q.06 What is a good birthday discount for customers? +
/ Answer
It depends on margin and how often customers buy. Many ecommerce brands use 10 to 20 percent off, a fixed dollar amount, a free gift with purchase or double loyalty points. A free gift or points multiplier often protects margin better than a percentage. Use unique, single-use codes with a clear expiry, typically two to four weeks, so the offer is not shared or stockpiled.
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