How to Create a Birthday Flow in Klaviyo

Birthday emails have the highest engagement rates of any automated email type. They outperform standard campaigns on every metric — open rates, click rates, conversion rates, and revenue per recipient — because they arrive at a moment when the customer is already feeling celebratory and receptive to treating themselves.

Yet most ecommerce brands either do not send birthday emails at all, or send a generic "Happy Birthday" message with a token discount that feels like an afterthought. A properly built birthday flow in Klaviyo goes further: it collects birthday data systematically, delivers a genuinely compelling offer at exactly the right time, and includes a follow-up to capture customers who did not convert on the first email.

We build birthday flows for every Klaviyo account we manage, and they consistently deliver some of the highest revenue-per-recipient numbers of any flow in the account. This guide covers every step, from collecting birthday data to designing emails that make your customers feel genuinely celebrated.

Why birthday flows work

Birthday emails work because of psychology, not just marketing. Here is why they are so effective:

• Emotional timing — the customer is already in a positive, celebratory mood and more open to treating themselves
• Personal connection — acknowledging someone's birthday makes them feel valued as an individual, not just a transaction
• Gift-giving culture — many people receive money or gift cards for their birthday and are actively looking to spend
• Self-treating mindset — birthdays are one of the few occasions where people give themselves permission to splurge
• Low competition — unlike Black Friday or Christmas, birthday emails arrive when the customer's inbox is not flooded with promotional messages

The data supports this. Birthday emails typically achieve open rates of 40-50% (versus 15-25% for standard campaigns), click rates of 10-15%, and conversion rates of 5-10%. These are exceptional numbers for automated emails.

Step 1: Collect birthday data

The biggest barrier to birthday flows is data collection. You cannot send a birthday email if you do not know when the customer's birthday is. Here are the most effective collection methods:

Method 1: Signup form field

Add a birthday field to your Klaviyo popup signup form. This captures birthday data at the point of first contact. To maximise completion rates, make the birthday field optional but clearly explain the benefit: "Share your birthday for a special treat on the day."

Method 2: Dedicated birthday collection campaign

Send an email to your existing list asking subscribers to share their birthday. Offer an immediate incentive (a small discount or free shipping) in exchange for providing the date. This is the fastest way to build birthday data for an existing list.

Method 3: Post-purchase email

Add a birthday collection request to your post-purchase email sequence. After the customer has received their order and had a positive experience, ask them to share their birthday for future rewards. The goodwill from a successful delivery makes them more likely to respond.

Method 4: Customer account

If your Shopify store uses customer accounts, add a birthday field to the account registration form. This data syncs to Klaviyo through the Shopify integration.

Method 5: Preference centre

Create a preference centre page where subscribers can update their profile, including their birthday. Link to this page from your email footer and periodic profile update requests.

For more on collecting and using customer data effectively, see our email segmentation guide.

Step 2: Create the birthday flow

1. In Klaviyo, go to Flows > Create Flow
2. Search for "Birthday" in the flow library, or click Create from Scratch
3. Name the flow "Birthday Flow" or "Happy Birthday"
4. Set the trigger type to Date Property
5. Select the date property that stores the birthday (commonly "Birthday" or "Date of Birth")
6. Click Create Flow

Step 3: Configure the trigger

The Date Property trigger has several configuration options:

Trigger timing

• On the anniversary — sends on the exact birthday each year
• Before the anniversary — sends X days before the birthday (good for pre-birthday teasers)
• After the anniversary — sends X days after (less common, used for belated birthday messages)

We recommend triggering on the day itself for the main birthday email, with an optional pre-birthday teaser 3-7 days before.

Flow filters

• Is subscribed to email marketing — only send to opted-in subscribers
• Has been active in the last 365 days — skip completely disengaged contacts

Conditional splits

• VIP status — give VIP customers a more generous birthday offer
• Number of orders — tailor messaging for first-time versus repeat customers
• Product category preference — show relevant product recommendations based on purchase history

Step 4: Design your birthday emails

Email 1: Happy Birthday (sent on the day)

Subject line examples:

• "Happy Birthday, [First Name]! Your gift is inside"
• "It is your birthday! Here is something special"
• "[First Name], we have a birthday surprise for you"

Email structure:

1. Celebratory headline — make it festive and personal
2. Brief, warm message — "We hope you have an amazing day. To celebrate, we have a special treat just for you."
3. The offer — prominently displayed with a clear discount code or gift voucher
4. Expiry date — give them 7-14 days to redeem (not just the birthday itself)
5. Product recommendations — personalised based on their browse and purchase history
6. CTA — "Treat Yourself" or "Claim Your Birthday Gift"

Keep the design celebratory but on-brand. Use your brand colours and typography, not generic birthday clip art. The email should feel like a thoughtful gesture from a brand they trust, not a mass-produced greeting card.

Step 5: Choose your birthday offer

The birthday offer should feel genuinely generous — more so than your standard promotions. Options include:

Offer type	Example	Best for
Percentage discount	20-25% off	Most ecommerce brands
Fixed amount voucher	£10-25 gift voucher	Brands with consistent AOV
Free gift	Free product with any purchase	Beauty, food, and sample-friendly brands
Free shipping	Free next-day delivery	Brands where shipping is a barrier
Loyalty points bonus	Double points on birthday purchase	Brands with loyalty programmes
Tiered by customer value	VIP: 25%, Standard: 15%	Brands with VIP segments

Use unique, single-use discount codes generated through Klaviyo's coupon feature. This prevents code sharing and lets you track birthday offer redemption rates accurately. For more on leveraging Klaviyo's essential flows, see our complete guide.

Step 6: Add a reminder email

Not everyone redeems their birthday offer immediately. A reminder email 3-5 days later catches those who intended to shop but forgot:

Subject line examples:

• "Your birthday treat expires soon!"
• "Do not forget your birthday gift, [First Name]"
• "Still time to treat yourself"

Reminder content:

• Acknowledge that their birthday may have been busy
• Remind them of the specific offer and expiry date
• Show personalised product recommendations
• Create gentle urgency — "Your [X]% discount expires in 3 days"

Add a conditional split before the reminder: if the customer has already placed an order since the birthday email, skip the reminder.

Advanced birthday strategies

Pre-birthday teaser

Send a teaser email 5-7 days before the birthday: "Something special is coming your way soon." This builds anticipation and primes the customer to look out for the birthday email. It also serves as a deliverability signal — the customer is more likely to open the birthday email if they are expecting it.

SMS birthday message

For customers who have opted in to SMS, send a short birthday text alongside the email. SMS birthday messages feel even more personal and have significantly higher open rates. Keep it brief: "Happy Birthday, [Name]! Your [X]% birthday discount is waiting: [link]"

VIP birthday escalation

Give VIP customers an elevated birthday experience: a more generous offer, a personalised message from the founder, or an exclusive birthday-only product. This reinforces their VIP status and strengthens the relationship. For more on VIP strategies, see our flow optimisation guide.

Birthday month campaigns

If you collect only birth month (not exact date), run a "birthday month" flow that triggers on the first day of the month. The messaging shifts from "Happy Birthday" to "It is your birthday month — celebrate all month long with this special offer." Less precise, but still effective.

Anniversary flow alternative

If birthday data collection proves difficult, create a "purchase anniversary" flow instead. This triggers on the anniversary of the customer's first purchase: "It has been one year since you joined us — here is a thank you." This requires no additional data collection since the purchase date is already in Klaviyo.

Birthday data enrichment

Run a quarterly campaign asking subscribers who have not provided their birthday to do so. Frame it as an opportunity: "We want to celebrate you! Share your birthday and unlock a special annual treat." Track the percentage of your list with birthday data and set a target to increase it each quarter.

Common mistakes to avoid

1. Not collecting birthday data

The flow is useless without data. If you do not actively collect birthdays, start now. Add the field to your signup form, run a collection campaign, and include it in your post-purchase sequence. Even if you only have birthday data for 30% of your list, that is 30% receiving a high-converting automated email.

2. Making the offer too small

A 5% birthday discount feels like an insult. If your standard promotions offer 10-15%, the birthday offer should be 20-25% or include a meaningful gift. The customer should feel genuinely celebrated, not patronised. Remember, this email has the highest conversion rate of any flow — a generous offer is an investment, not a cost.

3. Expiring the offer too quickly

Limiting the birthday offer to the birthday itself (24 hours) misses customers who are busy celebrating, travelling, or simply did not check their email. Give them at least 7 days, ideally 14, to redeem the offer.

4. Generic design

Using stock birthday imagery (balloons, cake, confetti) that clashes with your brand aesthetic makes the email feel impersonal. Design the birthday email in your brand style with a celebratory twist — use your fonts, colours, and photography style, just with warmer, more festive copy.

5. Not segmenting the offer

Sending the same 15% discount to a one-time buyer and a customer who has spent £2,000 with you is a missed opportunity. Use conditional splits to offer tiered birthday benefits based on customer value.

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Birthday flows are one of the simplest and highest-ROI automations you can build in Klaviyo. The setup is straightforward, the performance metrics are excellent, and the customer goodwill they generate is immeasurable.

Start with the basics: add a birthday field to your signup form, build a two-email flow (birthday + reminder), and offer something genuinely generous. Refine from there with pre-birthday teasers, VIP tiers, and SMS touchpoints.

The hardest part is data collection, and the solution is simply to start asking. Every birthday you capture is another high-converting email that fires automatically, year after year.

Need help building your birthday flow in Klaviyo? See our Klaviyo services or get in touch for a free account audit.