First Party and Zero Party Data for Shopify Brands: What to Collect and How to Use It

Key Takeaways

• First party data is what you collect yourself on your own channels; zero party data is what customers tell you on purpose, such as quiz answers and preferences.
• Safari has blocked third party cookies since 2020, Firefox has isolated them since 2022, and Google decided in 2025 to keep Chrome's choice based approach and retire most Privacy Sandbox replacements.
• Shopify Forms, customer metafields, segments and the customer privacy settings are the native tools; Shopify Audiences is US and Canada only.
• In Klaviyo, every extra form field becomes a custom property you can segment and personalise on, and multi step forms ask for interests after the email address, so the first step stays short.
• In the UK, marketing email and SMS to individuals need specific consent or the soft opt in, and the ICO says consent and legitimate interests are the lawful bases most likely to apply.
• Across our Klaviyo clients, the welcome series and abandoned cart flows are the best performing flows, and both run on first party data you already have.

Quick Answer

First party data is the information your Shopify store collects directly, from orders, browsing, email engagement and accounts; zero party data is what customers choose to tell you, through quizzes, preference forms and surveys. With third party cookies blocked in Safari and Firefox and Google keeping Chrome's choice based approach, this is the data that still works for personalisation and advertising. Collect it with Shopify Forms, metafields and Klaviyo sign up forms, store it against the customer profile, use it in segments, flows and ad audiences, and keep to UK consent rules for email and SMS.

Table of Contents

• First, Zero, Second and Third Party Data Defined
• Why It Matters Now: What Happened to Cookies
• What a Shopify Store Should Collect
• The Shopify Tools: Forms, Metafields, Segments and Privacy Settings
• Collecting and Using It in Klaviyo
• How to Use the Data
• UK Rules: Lawful Basis, Consent and PECR
• A 90 Day First Party Data Plan
• Why Matters Perspective
• Frequently Asked Questions
• Final Thoughts
• Related Articles

For years online stores borrowed data: tracking cookies, bought audiences and the ad platforms' knowledge of who everyone was. Much of that has gone. What remains is what customers do on your store and what they tell you, and the brands that collect and use it well have an advantage that cannot be bought. This guide explains the terms, the tools in Shopify and Klaviyo, and the UK rules.

First, Zero, Second and Third Party Data Defined

First party data is what your business collects directly from its own customers and visitors through its own channels: orders and order history, pages viewed, email opens and clicks, SMS replies, account details and support conversations. Zero party data is a term coined by Forrester for data that a customer intentionally and proactively shares with a brand, including preference centre data, purchase intentions, personal context and how the individual wants the brand to recognise them. Second party data is someone else's first party data shared with you directly, such as a retail partner's customer list. Third party data is bought from aggregators who collected it across many sites, usually through tracking cookies.

The distinction that matters in practice is between what you observe (first party) and what you ask (zero party). Observed data is plentiful but needs interpreting; asked data is scarce but exact. A customer who buys dog food every six weeks tells you something; a customer who says her dog is a nine year old Labrador on a diet tells you more.

Why It Matters Now: What Happened to Cookies

Sources: WebKit's announcement of full third party cookie blocking, Mozilla's announcement of Total Cookie Protection, and Google's Privacy Sandbox blog, which said in April 2025 that Chrome would maintain its current approach to offering users third party cookie choice rather than roll out a new prompt, and in October 2025 that it was retiring most Privacy Sandbox technologies, including Topics, Protected Audience and the Attribution Reporting API.

The result for a store is that cross site tracking no longer reaches a large share of shoppers, ad platforms rely more on what you send them, and consent banners reduce what even your own site can record. Shopify's privacy settings guide says non essential data is collected only after consent for UK and EEA visitors on new stores, and to expect decreased session counts as a result. Data you collect openly, with consent, is the part that keeps working.

What a Shopify Store Should Collect

Collect what you will use. Extra questions tend to lower the sign up rate, so ask one thing at sign up, more after the first order, and the rest in a quiz or preference centre the customer chooses to complete. Across our Klaviyo clients, the welcome series and abandoned cart flows are normally the best performing flows by revenue and conversion rate, and both run on data a store already has.

The Shopify Tools: Forms, Metafields, Segments and Privacy Settings

• Shopify Forms is Shopify's free app for pop up and inline forms. Shopify says you can customise a form to control what information it collects, attach a discount and tag customers, so a question on the form can feed a segment.
• Customer metafields (described in Shopify's custom data help) extend the customer record with your own fields, such as a loyalty tier or a stated preference, so the answers live in Shopify rather than only in an app.
• Customer segments are dynamic, rule based lists built from orders, tags, location and metafields, which Shopify Email, discounts and apps can use.
• Customer privacy settings run the cookie banner and tell Shopify's pixels what they may collect; our guide to Consent Mode v2 on Shopify covers the Google side.
• Shopify Audiences builds ad audiences from Shopify's network, but Shopify says it is available to eligible Shopify Plus stores based in the United States or Canada that use Shopify Payments, so it is not an option for UK stores.

Collecting and Using It in Klaviyo

Most of our clients use Klaviyo, and it is built for this. Klaviyo's help centre says that any additional field you add to a sign up form or subscribe page is collected as a custom property on the profile, with no limit on the number of properties, and that properties can be used in segments, flows and templates. Its multi step forms spread questions over up to four pages, so the email comes first and the interests or birthday come after, and the extra answers are kept once an email or phone number is given.

• Quiz apps such as Octane AI sync quiz answers to Klaviyo profiles for tagging and segments; a product quiz is the richest source of zero party data most stores have.
• Segments on properties: skin type, dog size, coffee strength, preferred frequency.
• Flows that branch on the answer, so the welcome series recommends the right product from the first email.
• Preference centres that let customers choose topics and frequency, which cuts unsubscribes.

Our guides to getting more email subscribers and what Klaviyo is cover the setup.

How to Use the Data

1. Personalise the first month. A welcome series that uses the quiz answer or the first product bought outperforms a generic one.
2. Time the replenishment. Order history tells you when a customer is due; a reminder a week before beats a discount a month after.
3. Build ad audiences from your own lists. Customer match in Google Ads and custom audiences in Meta take your first party lists, with lookalikes built from your best customers; see the Meta Pixel and Conversions API for sending purchase data server to server.
4. Improve the products. Quiz and survey answers show which needs you do not serve.
5. Cut returns. A stated size or skin type sent to the product page reduces wrong purchases.
6. Judge channels properly. First party revenue by source is the base of marketing attribution.

Customers accept this when it is open. Twilio Segment's State of Personalization report in 2022, from a survey of 3,450 consumers in 12 countries including the UK, found 63% comfortable with personalisation when brands use their own first party data, while only 40% trusted brands to use their data responsibly. The gap is the point: collect openly, explain why, and use it to be useful.

UK Rules: Lawful Basis, Consent and PECR

The ICO says the two lawful bases most likely to apply to sending direct marketing are consent and legitimate interests, but that PECR sometimes requires consent. Its guidance on electronic mail marketing, which covers SMS as well as email, says individuals must have specifically consented to electronic mail from you, with a soft opt in for an existing customer who bought or negotiated to buy a similar product or service, provided you gave a simple way to opt out when you collected their details and in every message. The ICO notes its guidance is under review following the Data (Use and Access) Act, so check for updates.

• Say what you collect and why in the privacy policy and at the point of collection.
• Keep the consent record: date, source and wording.
• Separate consents for email, SMS and WhatsApp; our SMS marketing guide covers texts.
• Treat quiz answers carefully. Health related answers, such as skin conditions or allergies, are special category data under UK GDPR and need explicit consent and a clear purpose.
• Honour opt outs and deletion requests across every tool the data has reached.

A 90 Day First Party Data Plan

1. Weeks 1 to 2: audit what you collect, where it is stored and what consent you hold; fix the consent banner and Consent Mode.
2. Weeks 3 to 4: add one question to the sign up form or a multi step form, and a metafield or property to hold it.
3. Weeks 5 to 8: launch a product quiz if your range needs one, and branch the welcome series on the answer.
4. Weeks 9 to 12: build segments and ad audiences from the data, send the server side purchase events to the ad platforms, and measure new customer rate and repeat rate against the quarter before.

Why Matters Perspective

We are a Klaviyo partner, and the stores we take on usually have more first party data than they use: years of orders, thousands of profiles and a welcome series that treats every subscriber the same. The quickest wins are rarely new tools; they are a question on the sign up form, a flow that branches on the answer and replenishment timing taken from the orders already in Shopify. Removing 5,000 unengaged profiles from a 45,000 profile list cut one client's Klaviyo bill to £600 a month with no drop in email revenue, which is the other side of first party data: keep what is useful and consented, and let the rest go.

We are a Shopify Select partner with Verified Skills across development and marketing, so the forms, metafields, flows and ad audiences can be built as one system. Our pricing is published, and retainer clients are billed one month in arrears with no long contracts. For a free review of your email and customer data, visit our email marketing agency page.

Frequently Asked Questions

What is first party data?

First party data is information your business collects directly from its own customers and visitors through its own channels: orders, browsing on your store, email and SMS engagement, customer accounts and support conversations. You own it, you collected it with the customer's knowledge, and no other company has the same set.

What is zero party data?

Zero party data is information a customer intentionally and proactively shares with a brand, a term coined by Forrester, which gives the examples of preference centre data, purchase intentions, personal context and how the individual wants the brand to recognise them. A product quiz answer, a stated skin type or a chosen email frequency are zero party data.

What is the difference between first, second and third party data?

First party data you collect yourself; second party data is another company's first party data shared with you directly; third party data is bought from aggregators that collected it from many sources, usually through tracking across websites. Browser changes have made third party data far less available, which is why first and zero party data now matter more.

Are third party cookies going away?

Mostly gone already, outside Chrome. Apple's Safari has blocked third party cookies by default since March 2020 and Firefox has isolated cookies per site since June 2022. Google said in April 2025 that Chrome would keep its current approach of offering users a choice rather than removing them, and in October 2025 retired most of its Privacy Sandbox replacements.

How can a Shopify store collect zero party data?

With Shopify Forms, which lets you customise what a form collects, attach a discount and tag customers; with customer metafields to store the answers; and with Klaviyo sign up forms, where any extra field is saved as a custom property, or multi step forms that ask for interests or a birthday. Product quizzes can sync answers to Klaviyo too.

Do I need consent to use first party data for marketing in the UK?

For email and SMS, usually yes. The ICO says the lawful bases most likely to apply to direct marketing are consent and legitimate interests, but that PECR sometimes requires consent, and that marketing email or text to individuals needs their specific consent, with a soft opt in exception for existing customers who bought or negotiated to buy a similar product, provided they can opt out easily every time.

Is Shopify Audiences available in the UK?

No. Shopify's help centre says Shopify Audiences is available to eligible Shopify Plus stores based in the United States or Canada that use Shopify Payments. UK brands build their own audiences from first party data instead, through customer segments, Klaviyo lists and the ad platforms' customer match tools.

Final Thoughts

First party data is what your store knows; zero party data is what your customers choose to tell you. With third party tracking shrinking, the two together are the only durable base for personalisation and advertising, and no competitor can buy them.

Collect a little, with consent, use it visibly, and add more as customers see the benefit. If you would like help building it into your Shopify store and Klaviyo account, email us.

Related Articles

• What Is Klaviyo?
• How to Get More Email Subscribers on Your Shopify Store
• Google Consent Mode v2 on Shopify
• Meta Pixel and Conversions API on Shopify
• Customer Journey Map Template for Ecommerce Stores
• Marketing Attribution for Ecommerce
• Klaviyo Pricing UK
• SMS Marketing for Shopify Stores