Short answer
Export the companies that fit your ICP with their name and website domain, save them as a UTF-8 CSV with the headers companyname and companydomain, and upload the file as a company list in Campaign Manager, or send it through the LinkedIn Marketing API (DMP segments). LinkedIn processes a list in up to 48 hours. It recommends at least 1,000 companies and accepts up to 300,000, and a DMP segment holds one list at a time, so replace the file when the list changes.
1. Pick the companies
Don’t send everything. Send companies that fit your ICP and showed intent: they came from a decision-stage question, read pricing or integration pages, or came back. In our dashboard that is every company with ICP fit 60 or more, and you can download the list from the LinkedIn ABM screen.
2. Format the CSV
LinkedIn reads a header row with at least one of these columns:
| Header | Also accepted | Use |
|---|---|---|
| companyname | – | The company’s name |
| companydomain | companyemaildomain, emaildomain, domain | Best match key for identified companies |
| companywebsite | website | If you have the full URL |
| linkedincompanypageurl | – | Most precise, when you have it |
| stocksymbol | stockticker, ticker | Listed companies only |
companyname,companydomain
Atlasstone Capital,atlasstonecapital.example
"Bluewind Group, Inc.",bluewindgroup.exampleRules: CSV, UTF-8, one company per row, no duplicate headers, and wrap a name in double quotes if it contains a comma.
3. Upload or sync
- Campaign Manager: upload the CSV as a company list in Matched Audiences. Fine for a weekly refresh.
- Marketing API: request an upload URL, upload the CSV, create a DMP segment of type company list, attach the file, and poll until the segment is ready. Then add the segment to your campaign’s targeting. Access is limited to developers LinkedIn approves, with the rw_ads and rw_dmp_segments permissions.
4. Wait for matching, then target
Processing takes up to 48 hours. A DMP segment holds one list upload, so to change it, replace the list. Once ready, add job function and seniority (see which roles to target) and check that the campaign audience is at least 300 members.
5. Keep it fresh
Companies identified from AI arrive every day. Refresh the list daily or weekly, and remove customers and open opportunities that sales already works, so LinkedIn budget goes to new accounts.
Questions
What is the minimum size of a LinkedIn company list?
LinkedIn doesn’t set a hard minimum for company lists but recommends at least 1,000 companies. The campaign itself needs at least 300 matched members to run.
How long does LinkedIn take to match a company list?
Up to 48 hours.
Should we include the domain or only the name?
Include the domain. Names are ambiguous; domains match better.
Facts checked against the sources below on 15 October 2026. AI ad platforms change quickly: if something here no longer matches what you see, tell us and we will update it.
