Google Ads Customer Match: eligibility, list formatting and PDPA consent

Google Ads Customer Match lets you upload information your customers gave you, such as email addresses and phone numbers, so Google can match it to signed-in Google users and show them ads on Search, the Shopping tab, YouTube, Gmail and Display. You can use the matched list to target or exclude those people, adjust bids for them, or feed them to Performance Max and Demand Gen as an audience signal. Access depends on your account's policy and payment record, and the upload must follow Google's formatting and hashing rules.

This guide walks through what Customer Match is, who is eligible, how to format and hash a list, why match rates vary, how the lists work in different campaign types, and what consent looks like when your customers are in Thailand. For help putting first-party audiences to work across an account, the Google Ads management service page explains how they fit with keywords, bidding and creative.

What is Google Ads Customer Match?

Customer Match is a way to reach people who already have a relationship with your business. You upload a customer list in Google Ads, Google compares the details with information in Google accounts, and the people it can match become an audience you can use in campaigns. People who do not have a Google account, or who signed up to your business with an email they do not use for Google, are not matched.

Typical uses include:

• Showing existing customers ads for a related product, a renewal or a loyalty offer.
• Excluding current customers from acquisition campaigns so the budget goes to new buyers.
• Telling Performance Max or Demand Gen what a valuable customer looks like, through an audience signal.
• Bringing back customers who have not bought for a long time.

Customer Match memberships expire after 540 days, so a list that is never refreshed slowly shrinks. Uploading new and updated customers on a regular schedule, by hand or through an automated connection, keeps the audience usable.

Who is eligible for Customer Match?

Google's Customer Match policy has two levels of access. The base level is open to accounts with a good history of policy compliance and a good payment history. That base access lets you use Customer Match lists in "Observation" mode and as exclusions.

The higher level unlocks the "Targeting" setting and manual bid adjustments on Customer Match lists. For that, the policy requires at least 90 days of Google Ads history and more than USD 50,000 in total lifetime spend. Accounts billed in other currencies have their spend converted to US dollars using the average monthly conversion rate. If your account does not meet that threshold, you can still upload lists and use them for observation, exclusions and as signals, but you cannot narrow a campaign to the list alone.

The policy also sets rules for every advertiser, whatever their spend:

• Upload only first-party data: information you collected from your own websites, apps, physical stores or directly from customers.
• Your privacy policy must disclose that you share customer data with third parties to perform services on your behalf.
• Obtain consent where the law or Google's policies require it.
• Upload data only through Google's approved interface or API.
• Do not upload data about children under 13, or data collected from sites or apps directed at them.
• Do not write ads that imply you know personal or sensitive information about the viewer.
• Do not combine a list with settings, such as very tight geographic limits, that narrow it to a small number of people.

Sensitive interest categories cannot be used for targeting through Customer Match, and Customer Match cannot be used to promote products or services in those sensitive categories.

How to format and hash a Customer Match list

The upload file must be a CSV encoded in ASCII or UTF-8. UTF-16 is not supported, which matters for Thai data exported from some spreadsheet tools. Column headers must be in English and use Google's names: Email, Phone, First Name, Last Name, Country, Zip, Mobile Device ID, and, outside the EEA, UK and Switzerland, User IP address and User Interaction timestamp. A timestamp cannot be sent without an IP address.

You can upload plain text or data you have already hashed. If you upload plain text through Audience manager, the email, phone and name fields are hashed on your computer before the file leaves it, using SHA-256. Country and Zip are not hashed. If you hash the data yourself, you must use hex SHA-256 and normalise each value first, or the hashes will not match Google's. Here is how each column should be prepared, based on Google's formatting guidelines:

A worked example shows why normalising matters. The address " Somchai.K@Gmail.com " with a leading space and capitals produces a completely different SHA-256 hash from "somchaik@gmail.com". Google can only match the second form, so a list hashed without normalising can upload without errors and still match almost no one. For Thai phone numbers, a local mobile number written as 08x-xxx-xxxx becomes +668xxxxxxxx in E.164: drop the leading zero, add +66, remove dashes and spaces.

Two further checks save time. First, remove duplicates and test addresses before upload so the reported size reflects real customers. Second, keep the raw file and the hashed file separate and store the raw file under the same access controls as the rest of your customer data. Hashed data is still customer data, so handle it with the same care.

What affects Customer Match match rates?

Google does not publish a standard match rate, and any figure you see quoted elsewhere describes someone else's list. What you can control is the quality of the input. The main factors are:

• Which email customers gave you. A work email or a rarely used address is less likely to be the one tied to a Google account.
• Formatting and normalisation. Unnormalised hashes, wrong phone formats and UTF-16 files all reduce matches.
• Number of identifiers per row. Supplying phone as well as email gives Google more than one way to match a customer.
• List age. Old lists contain more abandoned addresses and numbers.

Audience manager shows the matched size of each list by network after processing. Lists below Google's minimum size for a network will not serve there. Because these thresholds have changed over time, check the size column for each network in your account rather than relying on a fixed number.

How to use Customer Match in Search, Performance Max and Demand Gen

Search and Shopping

In Search campaigns, Customer Match lists can be added in Observation mode to see how customers behave and, for eligible accounts, in Targeting mode to restrict ads to the list. Observation is the usual starting point. It lets you compare conversion rates and order values for existing customers against everyone else before you change anything. Pairing a customer list with broader keywords can also work, because you are more willing to appear on a generic search when the person searching already buys from you.

Performance Max

In Performance Max, a customer list is one of the most useful parts of an audience signal, because it gives Google real examples of buyers rather than guesses. Remember that audience signals are hints, not limits; the campaign will still reach people outside the list. Customer lists also play a part in new customer acquisition goals, where you tell Google who your existing customers are so it can bid for new ones, or only for new ones.

Demand Gen and YouTube

Demand Gen campaigns can use customer lists as audiences on YouTube, Gmail and Discover placements, and as a seed for lookalike segments that find people with similar traits. Whether this is available depends on your account's Customer Match access level, so check in your account before planning around it. These placements reach people who are not actively searching, so a list of known buyers gives the campaign a starting point it would not otherwise have.

Automatic use in Smart Bidding

Google can use Customer Match lists automatically in Smart Bidding and optimized targeting, even in campaigns where you did not add them. Lists are not used this way in campaigns with manual bidding. If you do not want this, the account settings let you opt out of using all Customer Match lists for these features or exclude individual lists.

Consent and Thailand's PDPA

For customers in Thailand, uploading a list to Google Ads is a processing of personal data under Thailand's Personal Data Protection Act B.E. 2562 (PDPA). At a general level, the PDPA expects a business to have a lawful basis for each purpose it uses personal data for, consent being one of them, and to tell people how their data will be used and with whom it will be shared. Marketing use through an advertising platform is a purpose customers should be told about when their data is collected.

In practice that means checking a few things before the first upload. Does your sign-up form or LINE registration flow explain that contact details may be used for advertising, including on Google? Does your privacy notice say that you share data with service providers for that purpose, which Google's own policy also requires? Can you remove people who withdraw consent or ask to be deleted from future uploads? This guide is not legal advice, and how the PDPA applies to your business depends on how and why you collected the data. Speak to a qualified adviser for your situation, and see the data security and compliance service page for how consent records can be organised alongside marketing data.

What this means for Thai marketers

Thai businesses often hold customer contact details in several places: LINE Official Account, a CRM, an ecommerce platform and in-store sign-up sheets. Customer Match works best when those sources feed one clean list with consistent formatting, refreshed on a schedule. If many of your records hold a phone number but no email, getting the E.164 conversion right for +66 numbers decides how much of the list can match at all. If your customer data lives mostly in LINE, the LINE CRM service page explains how contact data can be collected with clearer consent and kept in one place.

Accounts below the USD 50,000 lifetime spend threshold should plan around Observation, exclusions and audience signals, which are available to every policy-compliant account. That still covers the most common uses: keeping existing customers out of acquisition spend and giving Performance Max a real picture of your buyers; check in your account whether lists can be used as Demand Gen audiences at your access level.

Google Ads Customer Match FAQ

Do I have to hash my Customer Match data before uploading?

No, you can upload plain text and Google Ads will hash email, phone and name fields with SHA-256 on your computer before upload. If you hash the data yourself, use hex SHA-256 and normalise each value first: remove spaces, convert to lowercase and format phone numbers to E.164.

Why can't I use Targeting mode with my customer list?

Targeting mode and manual bid adjustments on Customer Match lists require at least 90 days of Google Ads history and more than USD 50,000 in lifetime spend. Accounts that do not meet this can still use lists in Observation mode, as exclusions and as audience signals.

How long do people stay on a Customer Match list?

Customer Match memberships expire after 540 days. To keep a list at a usable size, upload new and updated customers regularly, either manually or through an automated connection.

Can I upload a list of email addresses I bought from a data provider?

No, Google's Customer Match policy allows only first-party data that you collected from your own websites, apps, stores or directly from customers. Purchased or rented lists are not first-party data.

Does Customer Match work with Performance Max?

Yes, customer lists can be added to Performance Max as part of an audience signal and are used for new customer acquisition goals. Signals guide the campaign but do not restrict it to the list.

Making customer data work in Google Ads

Google Ads Customer Match rewards clean data and clear consent more than list size. Normalise and hash correctly, refresh the list on a schedule, start in Observation mode, and make sure your privacy notice covers advertising use. If you want help setting up customer lists, exclusions and audience signals across your account, Relevant Audience can do it as part of its Google Ads management service.