Under 17 CFR 239.16b and General Instruction A, the company must already be an Exchange Act reporting company, must have filed all required reports during the preceding 12 months, and must not be a shell company or have been one within the previous 60 calendar days. A former shell company must have filed its Form 10 information at least 60 calendar days earlier.
For the form, "employee" is defined broadly to include directors, officers, general partners, and certain consultants and advisors, but only natural persons providing genuine services that are not tied to raising capital or promoting the stock.
An S-8 becomes effective automatically on filing, without waiting on SEC action, and post-effective amendments are effective on filing too. The plan prospectus described in Part I is delivered to participants but is not filed with the SEC. The filed document incorporates the company's periodic reports by reference and attaches exhibits under Item 601 of Regulation S-K, including a legal opinion for newly issued shares.
When a company adopts a new equity plan or adds shares to an existing one, an S-8 usually follows. Comparing the registered share count with the shares outstanding gives a rough sense of how much dilution stock compensation could add over time, and grants to officers and directors then show up on Form 4.