Lesson 2 of 8
Finding the document
Accession 0000018230-26-000008 is Caterpillar's fiscal 2025 10-K. What that number is, where the index lives, and how full-text search finds a phrase.
By Javier Sanz
Founder of ValueScreener. Built Ninety Nine, a securities services provider, and sold it to a tier-one global bank; ran operations and internationalization at Alpaca, the brokerage API.
Who writes thisEditorial processLinkedIn (opens in a new tab)X (opens in a new tab)
In one minute
- Every filing has an accession number, and that number identifies one document set permanently.
- A company's filing index is machine readable, so the whole history can be listed rather than browsed.
- Full-text search covers the words inside filings, which finds disclosures no form-type filter would.
EDGAR is the SEC's filing system, it is free, it requires no account, and it holds every document in this course.
Learning three things makes it usable: what an accession number is, where a company's index lives, and how to search inside documents rather than across titles.
One accession number, decoded
- 10000018230the filer that submitted it, here Caterpillar's own CIK
- 226the year of submission, 2026
- 3000008the eighth submission by that filer that year
The accession number
Every submission gets one, in the form 0000018230-26-000008. That example is Caterpillar's fiscal 2025 annual report, filed on 13 February 2026 for the year ended 31 December 2025.
It is not a document name. It identifies a submission, which may contain the main document plus exhibits, XBRL data files and the auditor's consent. A figure cited against an accession number can always be found again, because the number never changes and the filing is never edited in place.
A company also has a permanent identifier, the CIK, which is the Central Index Key. Caterpillar's is 18230, Walmart's is 104169, Verizon's is 732712.
Three routes to a document
A filing's own index page lives under the Archives path, built from the CIK and the accession number with its dashes removed. That page lists every file in the submission, and it is the link worth saving when citing a figure.
Full-text search finds what form types cannot
A form-type filter answers "which 8-Ks did this company file". It cannot answer "which companies disclosed a material weakness this quarter", because that phrase is in the text rather than in the metadata.
Full-text search covers the words inside filings from 2001 onward. It is the tool for finding a disclosure you can describe but not locate: a named critical audit matter, a specific accounting policy, a contract clause.
The structured data underneath
Every filing with financial statements carries XBRL, which tags each figure with what it is, the period it covers and the unit. The SEC republishes those tags per company, so a company's entire filed history of one line item can be retrieved as data with the fiscal year, the form and the filing date attached to each value.
That is how the ten-year series in the accrual course was built, and it is why every figure in these courses can name the filing it came from. A reader with a browser can check any of them.
Check yourself
What does an accession number identify?
- A single page of a filing
- One submission, permanently, including its exhibits and data files
- A company
Show the answer
Answer: B.
The company is identified by its CIK. The accession number identifies the submission, and it never changes, which is why it is the right thing to cite a figure against.You want every company that used a particular phrase in a filing. Which tool?
- The company search, filtered by form type
- Full-text search, which indexes the words inside filings
- The XBRL company facts endpoint
Show the answer
Answer: B.
Form type is metadata and cannot find a phrase. Full-text search covers the document text from 2001 onward, across all filers.How can a ten-year series of one line item be assembled without opening ten filings?
- It cannot; each year must be read separately
- From the XBRL data the SEC republishes per company, where each value carries its fiscal year, form and filing date
- By using the company's investor relations page
Show the answer
Answer: B.
Tagged financial data is published alongside the filings. Each fact carries its period, its form and the date it was filed, which is what makes a cited series checkable.Sources
- Caterpillar Inc., FY2025 Form 10-K, filed 13 February 2026, accession 0000018230-26-000008, used as the worked example of an accession number.
- The SEC's EDGAR system: the company search, the submissions endpoint on data.sec.gov, the full-text search service, and the XBRL company facts endpoint. All four were reachable and returned results on 16 September 2026.
What this leaves out
- EDGAR's interfaces and addresses change. The routes are described by what they do rather than by a URL, so the current documentation on sec.gov should be used rather than this page.
- Full-text search covers filings from 2001 onward. Older documents are on EDGAR and are not in that index.
- The submissions endpoint returns the most recent filings up to a limit, with older ones in separate files, so a count taken from it is a count of what it returned rather than of a company's whole history.
- XBRL tagging quality varies, and a figure retrieved from it should agree with the statement in the document before being relied on.