Customer Match eligibility and list retention
Customer Match allows advertisers to leverage first-party email and phone lists across Search, Shopping, and Audience campaigns with strict privacy safeguards.
What is Microsoft Customer Match?#
Customer Match allows brands to reach existing customers, lapsed buyers, and high-value CRM segments across Bing search, Microsoft Audience Network, and Copilot conversational answers.
Advertisers upload first-party contact lists formatted as SHA-256 cryptographic hashes as detailed in Microsoft Customer Match Documentation, 2026.
Account eligibility and compliance thresholds#
To unlock Customer Match capabilities, accounts must satisfy specific policy criteria: a positive payment history, at least 90 days of active advertising, and total historical account spend exceeding £5,000.
Customer data must be collected with direct, verifiable consent under GDPR, UK DPA, and applicable regional privacy laws.
Data formatting and SHA-256 hashing standards#
Contact records must be normalized (lowercased, trimmed whitespace) and hashed using the SHA-256 algorithm before submission as outlined in Microsoft Customer Match API Specs, 2026.
Strategic activation and bid adjustment tactics#
Apply Customer Match lists to bid up high-value VIP customers on expensive generic keywords (+100% bid adjustment), or exclude past purchasers from introductory offer campaigns (-100% adjustment).
Explore our Microsoft Ads Hub for advanced audience strategies.
Customer list deployment sequence#
Follow this five-step sequence to upload and activate first-party customer audiences.
- Step 1: CRM Export Export customer emails and phone numbers with explicit marketing consent.
- Step 2: Normalisation Lowercase text, remove special characters, and standardize country codes.
- Step 3: SHA-256 Hashing Hash data client-side or upload plain CSV via secure Microsoft portal.
- Step 4: Match Processing Allow 24 to 48 hours for Microsoft to complete account matching.
- Step 5: Campaign Association Attach audience list to target campaigns with custom bid modifiers.
Frequently asked questions#
What are the account requirements for Microsoft Customer Match?
Accounts typically require 90 days of advertising history, a clean policy compliance record, and a minimum cumulative spend threshold of £5,000.
How does Microsoft match uploaded customer lists?
Microsoft matches SHA-256 hashed email addresses and phone numbers against registered Microsoft Account profiles and authenticated network users.
How long does it take for a Customer Match list to process?
Customer match lists usually take between 24 and 48 hours to fully process and populate audience size metrics.
What is the minimum audience size required for Customer Match ads to serve?
Customer Match lists require a minimum of 300 matched active users within the Microsoft network before ads can begin serving.
How often should Customer Match lists be refreshed?
Lists should be refreshed at least monthly, with automated API synchronisation recommended for high-velocity customer databases.
Read more on this topic#
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