> Quick answer: Upload a CSV or TXT file (min. 1,000 entries, max. 1 GB) with email, phone, or MAID identifiers to TikTok Ads Manager under Assets > Audiences. TikTok matches and activates your audience within 24-48 hours.
Retargeting past customers on TikTok starts with a Customer File custom audience. Here is exactly how to build one.
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What is a TikTok Custom Audience?
Per TikTok's Business Help Center, a Customer File custom audience lets you match your existing customer data with real TikTok users. Upload identifiers you already have. TikTok does the matching.
Why use Customer File custom audiences
Retarget past buyers. Re-engage lapsed customers. Exclude current users from your acquisition campaigns. Customer File audiences also seed lookalike audiences, so you can find new users who resemble your best customers.
How TikTok matches your uploaded list
You upload a file containing user identifiers. TikTok hashes and compares those identifiers against its user base. Matched users form your custom audience. TikTok's documentation confirms the uploaded file is deleted automatically once matching is complete.
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File Requirements and Specifications
Get the file right before you upload. A formatting mistake means a failed match or a low match rate.
Supported ID types (email, phone, MAID)
TikTok accepts three identifier types:
- Email addresses
- Phone numbers
- Mobile Advertising IDs (IDFA for iOS devices, GAID for Android)
You can include multiple ID types in one file. Each column needs a header row labeled Email, Phone, or MAID. Per TikTok Ads Manager guidance, TikTok reads those headers to identify what it is matching.
File format and size limits
The file must be CSV or TXT format. Maximum size is 1 GB. Minimum is 1,000 entries. Upload fewer than 1,000 rows and TikTok will not process the file at all.
Hashing and normalization rules
TikTok accepts both original and pre-hashed values. Upload original values and TikTok hashes them automatically using SHA256 or MD5. Pre-hash yourself using only SHA256 or MD5.
Normalization is not optional. Emails must be lowercase with all spaces removed. Phone numbers must follow E.164 format: a plus sign, country code, then the number with no spaces or dashes. For example: +12025550198. MAIDs can be provided in uppercase or lowercase.
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Step-by-Step: Upload Your Customer List
Prepare your CSV or TXT file
Open a spreadsheet. Add one header row using the exact labels: Email, Phone, or MAID. List your identifiers below, one per row. Normalize everything before you export. Lowercase emails. E.164 phone numbers. Remove duplicates and invalid entries. Save as .csv or .txt.
Access Audience Manager in TikTok Ads Manager
- Log in to TikTok Ads Manager.
- Click Assets in the top navigation bar.
- Select Audiences.
- Click Create Audience, then choose Upload a Customer File.
Upload and name your audience
Select your file. Choose the ID type that matches your file's contents. Name the audience something specific and descriptive. "Customers Q3 2025 Email" is more useful six months from now than "Audience 1." A clear name saves real time when you are building campaigns later.
Wait for processing (24-48 hours)
TikTok processes the file and matches identifiers against its user base. Per TikTok's Business Help Center, this takes 24-48 hours. Your audience status will show Ready when matching is complete and the audience is available for use.
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Important Thresholds and Best Practices
Minimum audience size (1,000 matched users)
Your file must contain at least 1,000 entries to be processed. But TikTok also requires a minimum of 1,000 matched users after processing before the audience becomes available for campaigns. A large file does not guarantee a large audience. Match rate depends on how many of your customers are active TikTok users.
Audience Size Estimator tool
TikTok's Audience Size Estimator lets you preview potential reach before you commit budget to a campaign. Use it to sanity-check your audience size before launching.
Tips for higher match rates
Clean your list before upload. Remove bounced emails, duplicate rows, and incorrectly formatted phone numbers. Include more than one ID type when possible. A customer record with both an email and a phone number gives TikTok two chances to find a match instead of one.
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Next: Create Ads for Your Custom Audience
Your audience is ready. Now you need creatives that actually convert this segment. Retargeting audiences deserve ads that speak to people who already know your brand. Generic creatives waste the match work you just did.
Coinis generates on-brand ad creatives and copy from your product URL. Set up your Brand Profile once. Every creative after that reflects your brand voice, visual style, and audience context. When TikTok direct publishing rolls out in Coinis, your workflow carries straight through. For now, export your creatives from Coinis and upload them to TikTok Ads Manager directly.
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Frequently Asked Questions
What file formats does TikTok accept for customer list uploads?
TikTok accepts CSV and TXT files only. The file must be no larger than 1 GB and must contain at least 1,000 entries.
Do I need to hash my data before uploading to TikTok?
No. TikTok hashes original values automatically using SHA256 or MD5. You can pre-hash if you prefer, but only SHA256 and MD5 are supported.
How long does it take for a TikTok customer file audience to be ready?
TikTok processes and matches the file within 24-48 hours. The audience status will show Ready once it has at least 1,000 matched users and is available for campaigns.
What phone number format does TikTok require?
Phone numbers must follow E.164 format: a plus sign, the country code, then the full number with no spaces or dashes. For example: +12025550198.