SEC Forms Explained: 10-K, 10-Q, 20-F, and 6-K

If you pull filings for a living, or even just to size up a stock before you buy it, you learn fast that SEC forms aren't interchangeable. The form a company files depends on where it's incorporated, how big it is, and what it's disclosing. A German or Japanese company trading on the NYSE doesn't file a 10-K at all. Go looking for one and you'll come up empty, because it files a 20-F. Thousands of foreign companies list on US exchanges, and they run on a completely different set of forms than domestic filers.

So before you can read a company well, you need to know which form to open and what's actually inside it. Here's how the main ones break down, plus a handful of others that come up constantly.

The 10-K: the annual report for domestic companies

The 10-K is the most complete regular filing a US domestic company puts out. It's due within 60 days of fiscal year-end for large accelerated filers, and up to 90 days for smaller reporting companies. If you only read one document about a company all year, this is the one.

It's organized into four parts. Part I is the business itself: what the company does, its risk factors, and legal proceedings. Part II is where the money is, with the audited financial statements, management's discussion and analysis (the MD&A), and market data. Part III covers directors and executive information, often just pointed to the proxy statement by reference. Part IV holds exhibits and schedules.

The reason analysts live in the 10-K is that nothing else public is this detailed. The Part I business description is usually the most honest, thorough account you'll find of how a company actually operates, including its competition, customers, supply chain, intellectual property, and the regulations it lives under. The risk factors run heavy on boilerplate, sure, but buried in there are company-specific risks that genuinely tell you something. And the footnotes to the financials are gold. Accounting policies, segment results, contingencies, commitments, all the stuff that never makes it into an earnings press release lives in those notes.

A large-company 10-K can run well over a hundred pages, and the messiest ones stretch far past that. Don't try to read it front to back on the first pass. Skim Part I, then go straight to the MD&A and the footnotes.

Here's a quick example of why the footnotes earn their reputation. Say a company reports headline revenue that's up nicely year over year, and the stock pops on it. Open the segment footnote and you might find that one segment carried the whole increase while two others shrank. Or that the growth came from a segment with thin margins, so the extra revenue barely moved operating income. None of that shows up in the top-line number the press release leads with, but it's sitting right there in the notes, broken out segment by segment. That's the kind of thing that changes how you read the quarter.

The 10-Q: the quarterly check-in

The 10-Q is the lighter, quarterly cousin of the 10-K, filed after each of the first three fiscal quarters. There's no fourth 10-Q, because Q4 gets rolled into the annual 10-K, so you get three of these a year. For large accelerated filers it's due within 40 days of quarter-end.

It carries condensed, unaudited financial statements, an updated MD&A, and disclosures on anything that's changed since the last 10-K: legal matters, new risks, and so on. The whole value here is speed. The 10-K gives you the deep annual picture, and the 10-Q keeps you current on performance and on any new cracks forming in the business. Read the 10-Q's MD&A next to the earnings press release and you'll often catch context the press release quietly left out.

One thing to keep in mind: the numbers in a 10-Q are reviewed by the auditor, not audited. A review is a lighter touch and gives you less assurance than a full audit. In practice, material errors in quarterly statements are uncommon, but it's worth remembering that quarterly data is a notch less bulletproof than the annual figures.

The 20-F: the annual report for foreign private issuers

Foreign private issuers, or FPIs, that list on US exchanges file a 20-F where a domestic company would file a 10-K. It does the same job, an annual report to US investors, but the format and requirements differ in ways that matter.

First, the deadline. A 20-F is due four months after fiscal year-end, noticeably more generous than the 60-day clock on a large accelerated filer's 10-K. That extra runway reflects the work of preparing a filing that has to satisfy both home-country rules and US ones.

Second, and this is the big one, accounting standards. An FPI can file its financials under IFRS instead of US GAAP. The two frameworks have moved closer over the years, but real differences remain in areas like revenue recognition, lease accounting, and inventory. Inventory is a clean illustration. US GAAP still permits LIFO, the last-in-first-out method, while IFRS doesn't allow it at all. In a period of rising costs, a company using LIFO reports higher cost of goods sold and lower reported profit than the same company would under IFRS, and its inventory on the balance sheet sits at older, lower costs. So if you screen a US GAAP filer and an IFRS filer side by side on margins or inventory turns without noticing that, you can end up penalizing one of them for an accounting choice rather than an actual difference in the business.

Third, cadence. The 20-F carries no quarterly reporting requirement. FPIs file interim updates on Form 6-K, and they do it more or less at their own discretion, which I'll get to next. The upshot is that a foreign issuer may report results less often than a domestic one, leaving you with longer stretches where fresh numbers just aren't available.

Governance is different too. FPIs can be exempt from some US corporate governance standards as long as they follow their home-country rules, so the governance disclosures in a 20-F often look different from what you'd see in a domestic company's 10-K and proxy statement.

The 6-K: interim reports for foreign issuers

The 6-K is roughly the FPI version of the 8-K, with one important twist. An 8-K fires on a specific, listed set of triggering events. A 6-K has no such list. It's triggered whenever the company makes something public in its home country, has to file it with a foreign exchange, or sends it to shareholders.

In practice, FPIs use the 6-K to file earnings releases, interim financials, press releases about material events, and pieces of their annual reporting. But the timing and contents are far less predictable than an 8-K's. That's the catch for anyone tracking foreign names.

Because of that unpredictability, monitoring an FPI takes a bit more work than watching a domestic company. Often you'll want to keep an eye on both EDGAR, for the 6-K itself, and the company's home-country exchange, where the original announcement usually lands first.

Other forms worth knowing

Beyond the main four, a few other forms come up constantly in company work.

Form S-1. The registration statement a company files to go public. The S-1 is its first full public disclosure of the business, financials, and risks, and it's often more candid than the 10-Ks that follow, because the company is trying to win investors while underwriters and the SEC pick it apart.

DEF 14A. The proxy statement, filed ahead of the annual meeting. This is where executive compensation, board makeup, governance provisions, and shareholder proposals live. It's the governance companion to the financials in the 10-K.

Form 13F. The quarterly holdings report that institutional investment managers with at least $100 million in qualifying assets have to file. It reveals their positions, though on a lag, so you're always looking at a slightly stale snapshot.

Schedule 13D and 13G. Beneficial ownership reports triggered when an investor crosses 5% ownership in a company. A 13D generally signals activist intent, while a 13G signals passive ownership.

Form 4. Insider transaction reports, filed within two business days of a trade by an officer, director, or 10% holder. Good for spotting who's buying and selling their own stock.

Finding any of this on EDGAR

Everything above lives in one place, the SEC's EDGAR system at sec.gov. Search a company by name or ticker, land on its filings page, and you can filter by form type. Type 10-K in the filter and you get the annual reports. Type 20-F and you get the foreign annuals. Same for 8-K, DEF 14A, and the rest. A couple of habits make it faster.

Set up the full-text search when you're hunting for something specific, like a particular contract, a customer name, or a phrase in the risk factors, because it searches inside filing text rather than just the metadata. And when you open a foreign issuer, sort by form type and skim the 6-K stream first, since that's where their interim results and material news show up between annual 20-Fs. If you'd rather not live in EDGAR, plenty of tools sit on top of it and reshape the same public data into something more comparable, which is where a platform earns its keep.

Matching the form to the question

Most of company analysis is just knowing where to look, so here's the quick mapping I use.

• For deep annual data, read the 10-K (domestic) or 20-F (foreign).
• For quarterly updates, read the 10-Q (domestic) or hunt through 6-K filings (foreign).
• For material events between reports, check 8-Ks (domestic) or 6-Ks (foreign).
• For pay and governance, go to the DEF 14A proxy.
• For ownership and insider activity, pull 13D/13G, 13F, and Form 4.

When you're comparing a domestic company against a foreign one, stay alert to three things: the accounting standard (GAAP versus IFRS), the reporting frequency (quarterly versus roughly semi-annual), and the governance carve-outs FPIs can claim. Miss any of those and a side-by-side comparison can quietly mislead you.

All of these are free on EDGAR, so there's no gate between you and the source documents. That's part of what makes this work rewarding once you get comfortable with it. At FirmAdapt we spend a lot of time normalizing data across these filing types and reconciling GAAP and IFRS so cross-border comparisons hold up, but the underlying documents are sitting right there for anyone willing to open them. Learn which form answers which question, and the sheer depth of what's public about every listed company starts to feel like an edge rather than a chore.