Filing online (or E-filing) saves you time, it's painless, the IRS says it's 99% accurate, and it speeds any return you will receive.
Large corporations must file their corporate tax returns electronically. Here is the IRS requirement:
Corporations that have assets of $10 million or more and file at least 250 returns annually are required to electronically file their Forms 1120 and 1120S for tax years ending on or after December 31, 2006.
To file electronically, you will need to use one the IRS-approved E-File Providers. Choose a provider and follow the directions on their website. The IRS also has several payment options (debit or credit card and other), depending upon the form you are filing.

