SEC Filing Types: A Guide to the Forms Public Companies File

An SEC filing is any document a company, fund, adviser or individual submits to the Securities and Exchange Commission under federal securities law, and EDGAR is where nearly all of them become public. The form type, a short code like 10-K or 8-K, tells you what category of event or disclosure the filing covers before you open it. This guide groups the filing types that matter most to investors and developers by purpose, and points to where each one is covered in depth.

The main categories, at a glance

Periodic reports: the scheduled updates

Periodic reports are filed on a fixed cycle tied to a company's fiscal year, regardless of whether anything unusual happened:

• Form 10-K: the annual report, audited, filed once per fiscal year. See what is a 10-K filing for the full structure and deadlines.
• Form 10-Q: the quarterly report for the first three quarters of the fiscal year, reviewed but not fully audited.
• Form 20-F: the annual report used by foreign private issuers instead of a 10-K, with different disclosure accommodations. Covered in foreign private issuer.
• Form 6-K: a foreign private issuer's current report, roughly analogous to an 8-K but with more flexible timing tied to what the issuer discloses in its home market.

Current event reports: Form 8-K

Form 8-K is the one filing type triggered by events rather than a calendar. A company files one within four business days of specific events defined by the form's own item numbers, from an acquisition to an executive departure to a cybersecurity incident. Every 8-K item number explained covers the full list.

Ownership and insider filings

This group covers who holds a company's securities and when they trade them:

• Forms 3, 4 and 5 report an officer, director or 10% owner's holdings and transactions under Section 16 of the Exchange Act. See SEC Form 4 explained.
• Schedule 13D and Schedule 13G are filed by anyone who crosses 5% beneficial ownership of a company's voting shares; 13D signals possible intent to influence control, 13G is for passive holders.
• Form 13F is the quarterly holdings report filed by institutional investment managers with at least $100 million in qualifying securities.

Registration and offering filings

These forms cover securities being sold for the first time, under full registration or an exemption:

• Form S-1 is the standard registration statement for a public offering, including IPOs.
• Form D is a notice filing for an offering exempt from registration under Regulation D, mostly private placements. See Form D filings explained.
• Form C covers Regulation Crowdfunding offerings, capped in size and open to non-accredited investors through a registered funding portal.
• Form 1-A and related forms cover Regulation A offerings, a scaled-down registration path sometimes called a "mini-IPO."

Proxy and governance filings

A company's DEF 14A, its definitive proxy statement, is sent to shareholders ahead of an annual or special meeting and covers board elections, executive compensation and any shareholder proposals up for a vote. Related forms like DEFA14A cover additional soliciting material filed around the same vote.

Funds and investment advisers

Investment companies and advisers file their own set of forms, separate from operating companies:

• Form N-PORT reports a registered fund's portfolio holdings on a monthly basis.
• Form N-CEN is a fund's annual census filing, covering structural and operational information.
• Form ADV is filed by investment advisers to register with the SEC or state regulators and disclose their business, fees and disciplinary history.

Why there are more form types than this

A list like the one above covers the forms that come up in everyday financial research, but EDGAR's own filing-type browser lists far more distinct form codes than that. The reason is that EDGAR is not only for public operating companies: broker-dealers, municipal advisors, nationally recognized statistical rating organizations, clearing agencies, transfer agents and self-regulatory organizations like exchanges all file their own specialized forms with the SEC, most of which never appear in financial news because they are narrow, procedural, or aimed at a regulator rather than an investor. A handful of form types also exist only as amendments or withdrawal notices to a base form, such as a 10-K/A or an NT 10-K, which multiplies the list further without adding new categories of disclosure.

Filtering filings by form type

EDGAR lets you search by form type one filing or one company at a time. For cross-company queries, or to see everything filed under a given form type on a specific day, that gets slow quickly. SecFeed's filing search and daily ingestion log both accept an exact form type:

curl "https://secfeedapi.com/v1/ingestion-log?date=2026-10-09" \
  -H "Authorization: Bearer YOUR_API_KEY"

from secfeed import Client

sf = Client("YOUR_API_KEY")
filings = sf.filings('formType:"SC 13D" AND filedAt:[2026-09-01 TO 2026-09-30]')
for f in filings:
    print(f["companyName"], f["formType"], f["filedAt"])

The ingestion log call returns every form type EDGAR published on that date with a count for each, which is a quick way to see the real spread of form types on an ordinary day, not just the common dozen. The filing search query above uses the same formType field with a Lucene-style query to pull one specific form type across a date range, and the same pattern works for any form code, including the CUSIP-bearing filings covered in CUSIP lookup.

Frequently asked questions

What is the difference between a form type and a filing?

The form type is the category code, like 10-K or 8-K, defined by SEC rules. A filing is one specific submission of that type by one company on one date, identified by its own accession number.

How many different SEC form types are there?

More than the common dozen people think of as "SEC filings." EDGAR's filing-type list covers operating companies, investment companies, investment advisers, broker-dealers and several other regulated entity types, each with their own forms, plus amendment and withdrawal variants of many base forms.

Do all SEC filings come from public companies?

No. While 10-Ks, 10-Qs, 8-Ks and proxy statements come from public operating companies, EDGAR also hosts filings from investment advisers, mutual funds, broker-dealers and other regulated entities that are not publicly traded companies at all.

Which SEC form should I check first for a company I am researching?

For a broad view, start with the 10-K for the full annual picture, then check recent 8-Ks for anything that happened since. If you care about who owns the stock, Forms 3, 4 and 5 cover insiders, and Schedule 13D or 13G cover anyone over 5% ownership.

Is there one API that covers every SEC form type?

The SEC's own EDGAR system is the authoritative source for every form type, but it is organized by filing and by company rather than by business question. SecFeed parses the most commonly used form types into structured, queryable data; see the EDGAR filing search API for searching across all form types by keyword, date and company.