LinkedIn Matched Audience CSV: Contact List Headers, Company Lists and the 300-Member Minimum

A LinkedIn Matched Audience contact list is a CSV whose headers are LinkedIn's own names: email, firstname, lastname, jobtitle, employeecompany and country. A company list uses a different set, such as companyname and companywebsite. LinkedIn says lists have to follow its formatting guidelines or the upload won't succeed. The LinkedIn matched audience CSV formatter turns a lead export into either file in your browser. Before you upload, check the emails, because a list that falls short of LinkedIn's 300-member minimum won't serve.

Format a LinkedIn list →

The headers LinkedIn supports

From LinkedIn's help page on matched audience list troubleshooting, read on 9 November 2026:

Contact list headers

Header	Notes
email	The main match field
firstname, lastname	Name match
jobtitle	Optional
employeecompany	Optional
country	Optional
appleidfa, googleaid, googleuid	Mobile advertising IDs

Company list headers

companyname, companywebsite, companyemaildomain, linkedincompanypageurl, stocksymbol, industry, city, state, companycountry, zipcode.

LinkedIn's upload page tells you to start from the CSV templates it links, because lists "need to adhere to LinkedIn's formatting guidelines." If you build the file by hand, copy the header row from the template exactly. Don't use two names for the same field, such as both firstname and fn.

Contact list or company list?

• Contact list: people. Good for retargeting leads, nurturing customers or excluding them from prospecting campaigns. Email gives the strongest match; names and company help.
• Company list: accounts. Good for account-based campaigns where you want everyone at a set of companies, not named people. A website or email domain column lets LinkedIn find the company.

If your lead export has work emails, you can derive company domains from them. Free-mail domains such as gmail.com say nothing about an employer, so leave those rows out of a company list. Tell if an email is Gmail, Outlook or company covers how to split them.

Uploading in Campaign Manager

LinkedIn's upload page gives these steps:

1. Open your ad account in Campaign Manager and go to Plan, then Audiences.
2. Click Create audience, then select Matched Audience.
3. Select Company / Contact, then click Next.
4. Name the audience, choose the list type, and click Select list to pick your CSV.
5. Click Agree & Upload.

The page says the list has to be uploaded and matched before you can add it to your audience setup. It gives no timeframe for that, so check back rather than assuming it is instant.

The 300-member minimum

LinkedIn's page says: "The minimum ad set audience size is 300 member accounts." It also says location is a required targeting facet and may reduce your audience, so the segment should match more than 300 members.

What that means in practice: not every row will match a member, and a location setting can trim the audience further, so a list only a little over 300 rows may not serve. Anything that shrinks the list, including dead emails, counts against you.

The match rate depends on your data, so we can't predict it. Upload, see the matched audience size LinkedIn reports, and compare it to your row count.

Why verify emails first

LinkedIn matches on the address a person uses on LinkedIn. You can't verify that, but you can find the addresses that don't exist at all:

• Old lead exports collect closed work mailboxes whenever someone changes jobs.
• Webinar and trade-show lists have typos and one-time addresses.
• Scraped or purchased lists have the lowest quality of all.

An address that bounces today can't match a member. Removing it doesn't cost you any real audience, and it gives a clearer picture of how big the list is. Upload the file at /verify, suppress the invalid rows and keep the valid ones. For lists that came from a sales tool, clean a Sales Navigator lead list and clean LinkedIn URLs and dedupe leads go into more detail.

If the same people are in more than one export, remove duplicate emails first so you know the real size.

A clean process, in order

1. Export the leads or customers you want to reach.
2. Verify emails at /verify and drop invalid rows.
3. Format with the formatter, choosing Contact or Company mode. Compare the header row it writes with LinkedIn's current template before you upload.
4. Upload in Campaign Manager and wait for the match.
5. Check the size against 300, with your location targeting applied.
6. Refresh the audience as the list changes. Add new leads, remove people who became customers if you don't want to advertise to them.

Mistakes that cause rejected uploads

• Headers that aren't LinkedIn's names, or that repeat.
• A file that isn't a real CSV, for example an Excel file renamed.
• Header cells with stray spaces or capital letters copied from another tool.
• Merged name columns like "Jane Doe" in one cell with no firstname and lastname.
• Garbled characters from the wrong encoding. The CSV encoding fixer repairs those.

What the formatter does and doesn't do

• It finds columns by header name. Rename odd headers to Email, Name or Company first.
• It writes either a contact or a company file, and optionally hashes emails.
• It reads and formats the file in your browser; nothing is uploaded to SimpleVerifier.
• It can't make a list bigger, make a closed address match, or check what LinkedIn will match. Only the upload shows that.

Quick answers

• Is a CSV from Apollo or Sales Navigator ready to upload? Not as it comes. Their headers differ from LinkedIn's, so format it first.
• Can I upload personal emails? You can, but personal addresses often differ from what a person uses on LinkedIn.
• What if my list is under 300? Add more source rows, or use a company list, or accept that the audience may not serve.

Try it on your own list

Upload a sample at /verify. The first 100 checks are free with a Google sign-in, no card.

Pro, $39 a month: Unlimited email verification.* Never metered, never cut off. See pricing.

*Fair use: the first 100,000 checks a month at full speed, then slower, never cut off.