Company reports
8-K vs 10-K: what’s the difference?
Updated
The names sound like siblings, but the 8-K and 10-K do opposite jobs. The 10-K is the audited annual report: comprehensive, scheduled, and backward-looking. The 8-K is the current report: narrow, unscheduled, and filed within days of a material event. One is the encyclopedia; the other is the news bulletin.
Timing and trigger
A 10-K is filed once per fiscal year, on a deadline set by company size: 60 days after year end for large accelerated filers, 75 for accelerated filers, 90 for everyone else. An 8-K has no schedule at all. It is triggered by events, and for most items must be filed within four business days of the event occurring. A company files exactly one 10-K a year but may file dozens of 8-Ks.
Scope and assurance
The 10-K covers everything: the business description, risk factors, legal proceedings, MD&A, and full-year financial statements audited by an independent accounting firm, with CEO and CFO certifications attached. An 8-K covers one thing, such as a signed merger agreement, an executive departure, an earnings release or an auditor change, usually in a few paragraphs plus exhibits. Nothing in an 8-K is audited.
They also differ in liability mechanics. The 10-K is “filed” in its entirety and carries full Exchange Act liability. Parts of many 8-Ks, notably earnings releases under Item 2.02, are only “furnished,” a lighter standard companies use deliberately.
How they work together
In practice the two forms interlock. Fourth-quarter and full-year results usually reach the market first as an earnings 8-K; the audited detail follows in the 10-K days or weeks later, where footnotes and MD&A can quietly recast the press-release narrative. An acquisition announced in an Item 1.01 8-K shows up months later in the 10-K’s financials as goodwill, intangibles, and integration risk. Reading the year’s 8-Ks and then the 10-K is reading the same story twice: once as it happened, once as the lawyers and auditors settled it.
See it on a real company
The pattern is easiest to see on a live timeline. Apple’s filings page lets you filter by form type and watch 8-Ks cluster between the annual 10-K filings, and Apple’s financials show the audited results those filings feed. Report dates for the whole market are on the earnings calendar.
The 10-Q sits between the two: scheduled like the 10-K but unaudited and condensed, it updates the annual picture three times a year while 8-Ks fill the gaps in between. And when something in a past 10-K turns out to be wrong, the correction itself arrives as an 8-K, an Item 4.02 non-reliance notice, followed by an amended annual report. The forms reference each other constantly; fluency means knowing which document will carry which piece of news.
Rule of thumb: use 8-Ks to learn what changed this week, and the 10-K to understand what it means for the business as a whole.