The primary difference between form 1120 and form 1120S is that form 1120 is filed by regular corporations while form 1120S is filed by S corporations, which have elected 'S' status. Both forms are submitted annually under the Internal Revenue Service (IRS) code. This distinction affects the tax treatment and eligibility of the entities involved.

1. Primary difference between the income sections for form 1120 and 1120s
Primary difference between the income sections for form 1120 and 1120s
Solution
Answer :- The primary difference between form 1120 and 1120s is that the form 1120 is filed by
corporations on annual basis under internal revenue service (IRS) code whereas the form 1120s
is filed by S corporation (corporation who have opted for "S" status) on annual basis under
internal revenue service (IRS) code.