What are a CIK and an accession number?

Every document on EDGAR can be found with two numbers: the CIK of the company and the accession number of the filing. Both appear on every filing index page, in every API response and in every URL under sec.gov/Archives. Learning to read them makes EDGAR much faster to navigate.

What is a CIK?

The Central Index Key is a unique number the SEC assigns to each person or entity that files on EDGAR: companies, funds, individual insiders filing Form 4, filing agents and others. Key properties:

• It is permanent. A company keeps its CIK when it changes name, ticker or listing venue.
• It is not a ticker. Tickers belong to exchanges and can be reassigned; the CIK belongs to the filer.
• It is up to ten digits. EDGAR pages often show it without leading zeros (Apple Inc. is 320193), while the data APIs use the zero-padded ten-digit form (0000320193).

Individuals get CIKs too. A director filing a Form 4 has their own CIK, and the Form 4 appears under both the person and the company.

How do you find a CIK?

Three easy ways:

1. Search the company on sec.gov/edgar/search. The CIK is shown on its filing page.
2. Use the SEC’s ticker-to-CIK JSON file, which maps current tickers to CIKs and company names.
3. Read it off any filing: the cover page of most reports and the filing index both show it.

On the Filings Docket, every company page shows the CIK beside the company name.

What is an accession number?

Each submission accepted by EDGAR receives an accession number, an 18-digit identifier usually written with two dashes, for example 0000320193-26-000020. It has three parts:

Part	Example	Meaning
First 10 digits	0000320193	CIK of the entity that submitted the filing
Next 2 digits	26	Year of the submission
Last 6 digits	000020	Sequence number of that submitter’s filings in the year

The first part is the submitter, which is not always the company the filing is about. Many companies use filing agents, and their filings carry the agent’s CIK. In our October 2026 snapshot, for example, Apple’s 10-Q filed July 31, 2026 carries accession 0000320193-26-000020, beginning with Apple’s own CIK, while recent Form 4 filings about Apple insiders begin with 0001140361, the CIK of the agent that submitted them. A Form 4 filed by a company’s staff on behalf of a director often carries the company’s CIK even though the reporting person is the director.

How do you build a filing URL?

Filings are stored under the EDGAR archives path:

https://www.sec.gov/Archives/edgar/data/{CIK without leading zeros}/{accession number without dashes}/

The filing index page for the example above would be:

https://www.sec.gov/Archives/edgar/data/320193/000032019326000020/0000320193-26-000020-index.htm

That index lists every document in the submission. The main document’s file name comes from the filer, so you read it from the index or from the primaryDocument field in the submissions API.

The Filings Docket builds every “view on SEC.gov” link this way, from the CIK and accession number in the SEC’s own data, so each link goes to the original record.

Where do these numbers appear in the data API?

The submissions endpoint at data.sec.gov/submissions/CIK##########.json returns a company’s identifying details and a filings.recent block with parallel arrays: accessionNumber, filingDate, reportDate, form, items (for 8-Ks), primaryDocument and others. Each index across the arrays is one filing. The SEC asks automated users to declare a descriptive User-Agent and to stay within its fair-access rate limit.

Why this matters for readers

• Citing a filing precisely. An accession number points to one specific submission, which is more exact than “Apple’s 10-K”.
• Spotting amendments. An amended filing such as a 10-K/A has its own accession number; compare both.
• Avoiding ticker mix-ups. When two companies have had the same ticker at different times, the CIK resolves the ambiguity.

For a broader walkthrough, see how to search SEC EDGAR.